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Allowance for doubtfull receivables


	December 31, 2017		December 31, 2016
Cash on hand and at banks	$	127,625	$	126,584
Short-term deposits and highly liquid funds		7		9,408
Cash and cash equivalents	$	127,632	$	135,992

Accounts Receivable, Net (Tables)

12 Months Ended

Dec. 31, 2017

ACCOUNTS RECEIVABLE,NET [Abstract]

Accounts receivable, net

	December 31, 2017		December 31, 2016
Accounts receivable	$	80,037	$	85,266
Less: provision for doubtful receivables		(19,706)		(19,437)
Accounts receivable, net	$	60,331	$	65,829


Allowance for doubtful receivables	Balance at Beginning of Period		Charges to Costs and Expenses		Amount Utilized		Balance at End of Period
Year ended December 31, 2015	$	(18,464)	$	(59)	$	245	$	(18,278)
Year ended December 31, 2016	$	(18,278)	$	(1,304)	$	145	$	(19,437)
Year ended December 31, 2017	$	(19,437)	$	(269)	$	—	$	(19,706)

Prepaid Expenses and Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2017

PREPAID EXPENSES AND OTHER CURRENT ASSETS [Abstract]

Prepaid expenses and other current assets


	December 31, 2017		December 31, 2016
Prepaid voyage and operating costs	$	8,022	$	8,352
Claims receivable		12,307		9,822
Prepaid other taxes		4,520		4,279
Advances for working capital purposes		18		4,486
Other		2,516		1,957
Total prepaid expenses and other current assets	$	27,383	$	28,896

Vessels, Port Terminal and Other Fixed Assets, Net (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2018

Dec. 31, 2017

Vessels, Port Terminals and Other Fixed Assets, net


Vessels, Port Terminals and Other Fixed Assets, net	Cost			Accumulated Depreciation			Net Book Value
Balance December 31, 2017	$	2,553,047		$	(743,822	)	$	1,809,225
Additions		6,493			(71,062	)		(64,569	)
Impairment losses		(59,003	)		43,999			(15,004	)
Vessel disposals		(94,767	)		—			(94,767	)
Other disposals		(156	)		137			(19	)
Write offs		(55	)		21			(34	)
Vessel acquisition		10,255			(53	)		10,202
Transfers from deposits for vessels, port terminal and other fixed assets, net		49,421			—			49,421
Transfers to other long term-assets		(26	)		—			(26	)

Balance September 30, 2018	$	2,465,209		$	(770,780	)	$	1,694,429


Vessels	Cost		Accumulated Depreciation		Net Book Value
Balance December 31, 2014	$	1,841,140	$	(376,794)	$	1,464,346
Additions		—		(70,894)		(70,894)
Balance December 31, 2015		1,841,140		(447,688)		1,393,452
Additions		60,115		(73,847)		(13,732)
Transfers		29,695		—		29,695
Balance December 31, 2016		1,930,950		(521,535)		1,409,415
Additions		—		(73,017)		(73,017)
Impairment losses		(104,157)		58,034		(46,123)
Disposals		(11,828)		—		(11,828)
Balance December 31, 2017	$	1,814,965	$	(536,518)	$	1,278,447

Port Terminals (Navios Logistics)	Cost		Accumulated Depreciation		Net Book Value
Balance December 31, 2014	$	106,399	$	(20,467)	$	85,932
Additions		2,287		(3,431)		(1,144)
Balance December 31, 2015		108,686		(23,898)		84,788
Additions		2,051		(3,493)		(1,442)
Transfers		(1,513)		—		(1,513)
Balance December 31, 2016		109,224		(27,391)		81,833
Additions		5,060		(5,237)		(177)
Transfers from deposits for vessels, port terminals and other fixed assets		137,357		—		137,357
Balance December 31, 2017	$	251,641	$	(32,628)	$	219,013


Tanker vessels, barges and pushboats (Navios Logistics)	Cost		Accumulated Depreciation		Net Book Value
Balance December 31, 2014	$	464,966	$	(111,137)	$	353,829
Additions		6,188		(20,007)		(13,819)
Restructure of capital lease		(210)		—		(210)
Balance December 31, 2015		470,944		(131,144)		339,800
Additions		738		(18,894)		(18,156)
Transfers		3,696		—		3,696
Balance December 31, 2016		475,378		(150,038)		325,340
Additions		5,531		(17,603)		(12,072)
Disposals		(3,585)		3,585		—
Revaluation of vessels due to termination of capital lease obligation		(5,243)		—		(5,243)
Balance December 31, 2017	$	472,081	$	(164,056)	$	308,025


Other fixed assets	Cost		Accumulated Depreciation		Net Book Value
Balance December 31, 2014	$	13,426	$	(6,390)	$	7,036
Additions		443		(1,558)		(1,115)
Balance December 31, 2015		13,869		(7,948)		5,921
Additions		2,250		(1,475)		775
Transfers		(2,183)		—		(2,183)
Balance December 31, 2016		13,936		(9,423)		4,513
Additions		531		(1,257)		(726)
Disposals		(75)		28		(47)
Write offs		(32)		32		—
Balance December 31, 2017	$	14,360	$	(10,620)	$	3,740


Total	Cost		Accumulated Depreciation		Net Book Value
Balance December 31, 2014	$	2,425,931	$	(514,788)	$	1,911,143
Additions		8,918		(95,890)		(86,972)
Restructure of capital lease		(210)		—		(210)
Balance December 31, 2015		2,434,639		(610,678)		1,823,961
Additions		65,154		(97,709)		(32,555)
Transfers		29,695		—		29,695
Balance December 31, 2016		2,529,488		(708,387)		1,821,101
Additions		11,122		(97,114)		(85,992)
Impairment losses		(104,157)		58,034		(46,123)
Disposals		(15,488)		3,613		(11,875)
Write offs		(32)		32		—
Revaluation of vessels due to termination of capital lease obligation		(5,243)		—		(5,243)
Transfers from deposits for vessels, port terminals and other fixed assets		137,357		—		137,357
Balance December 31, 2017	$	2,553,047	$	(743,822)	$	1,809,225

Intangible Assets Other Than Goodwill (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2018

Dec. 31, 2017

INTANGIBLE ASSETS OTHER THAN GOODWILL [Abstract]

Schedule of intangible assets


Intangible assets		September 30, 2018			December 31, 2017
Acquisition cost (*)		$	190,212		$	200,610
Accumulated amortization			(77,924	)		(73,790	)
Write offs			—			(10,398	)

Total Intangible assets net book value		$	112,288		$	116,422

(*)	As of both September 30, 2018 and December 31, 2017, intangible assets associated with the favorable lease terms included an amount of $1,150 related to purchase options for the vessels.


	Acquisition Cost		Accumulated Amortization		Write off		Net Book Value December 31, 2017
Trade name	$	100,420	$	(45,156)	$	—	$	55,264
Port terminal operating rights		53,152		(10,889)		—		42,263
Customer relationships		35,490		(17,745)		—		17,745
Favorable lease terms(*)		11,548		—		(10,398)		1,150
Total Intangible assets	$	200,610	$	(73,790)	$	(10,398)	$	116,422

Net Book Value of Intangible Assets/Liabilities other than Goodwill as at December 31, 2016


	Acquisition Cost		Accumulated Amortization		Write off		Net Book Value December 31, 2016
Trade name	$	100,420	$	(41,303)	$	—	$	59,117
Port terminal operating rights		53,152		(10,162)		—		42,990
Customer relationships		35,490		(15,971)		—		19,519
Favorable lease terms(*)		82,485		(6,359)		(70,937)		5,189
Total Intangible assets		271,547		(73,795)		(70,937)		126,815
Unfavorable lease terms(**)		(24,721)		—		24,721		—
Total	$	246,826	$	(73,795)	$	(46,216)	$	126,815

(*)

(**)

Amortization expense


	Amortization Expense and Write Offs Year Ended December 31, 2017		Amortization Expense and Write Offs Year Ended December 31, 2016		Amortization Expense and Write Offs Year Ended December 31, 2015
Trade name	$	3,853	$	3,902	$	3,811
Port terminal operating rights		727		706		1,006
Customer relationships		1,775		1,775		1,775
Favorable lease terms		4,038		17,260		32,444
Unfavorable lease terms		—		(7,526)		(14,615)
Total	$	10,393	$	16,117	$	24,420

Schedule of aggregate amortization expense


Period
Year One	$	5,581
Year Two		5,588
Year Three		5,581
Year Four		5,581
Year Five		5,581
Thereafter		83,226

Total	$	111,138


Description	Within one year		Year Two		Year Three		Year Four		Year Five		Thereafter		Total
Trade name	$	2,811	$	2,811	$	2,818	$	2,811	$	2,811	$	41,202	$	55,264
Port terminal operating rights		985		985		985		985		985		37,338		42,263
Customer relationships		1,775		1,775		1,775		1,775		1,775		8,870		17,745
Total amortization	$	5,571	$	5,571	$	5,578	$	5,571	$	5,571	$	87,410	$	115,272

Accrued Expenses and Other Liabilities (Tables)

12 Months Ended

Dec. 31, 2017

ACCRUED EXPENSES AND OTHER LIABILITIES [Abstract]

Accrued expenses and Other Liabilities


	December 31, 2017		December 31, 2016
Payroll	$	18,889	$	14,730
Accrued interest		32,555		36,273
Accrued voyage expenses		4,843		2,217
Accrued running costs		23,812		21,394
Provision for estimated losses on vessels under time charter		2,631		3,129
Audit fees and related services		364		266
Accrued taxes		5,376		5,092
Professional fees		2,236		1,707
Other accrued expenses		4,153		6,941
Total accrued expenses	$	94,859	$	91,749

Borrowings (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2018

Dec. 31, 2017

BORROWINGS [Abstract]

Loans' outstanding amounts


Facility	September 30, 2018			December 31, 2017
Secured credit facilities	$	167,393		$	219,856
2022 Senior Secured Notes		305,000			305,000
2022 Notes		614,339			650,000
2022 Logistics Senior Notes		375,000			375,000
Navios Logistics other long-term loans and notes payable		166,853			167,912

Total borrowings		1,628,585			1,717,768

Less: current portion, net		(32,851	)		(33,885	)
Less: deferred finance costs, net		(29,254	)		(35,280	)

Total long-term borrowings	$	1,566,480		$	1,648,603


Navios Holdings borrowings	December 31, 2017		December 31, 2016
Commerzbank A.G. ($240,000)	$	—	$	19,857
HSH Nordbank ($15,300)		14,535		—
Loan Facility Credit Agricole ($40,000)		17,674		18,880
Loan Facility Credit Agricole ($23,000)		14,074		14,755
Loan Facility Credit Agricole ($23,000)		14,450		15,150
Loan Facility DVB Bank SE ($72,000)		50,140		54,540
Loan Facility DVB Bank SE ($41,000)		33,816		37,293
Loan Facility Credit Agricole ($22,500)		15,188		16,313
Loan Facility DVB Bank SE ($40,000)		18,254		28,000
Loan Facility Alpha Bank ($31,000)		25,600		27,400
Loan Facility Alpha Bank ($16,125)		16,125		16,125
Navios Acquisition Loan		—		51,240
2019 Notes		—		291,094
2022 Senior Secured Notes		305,000		—
2022 Notes		650,000		650,000
Total Navios Holdings borrowings	$	1,174,856	$	1,240,647


Navios Logistics borrowings	December 31, 2017		December 31, 2016
2022 Logistics Senior Notes	$	375,000	$	375,000
Navios Logistics Notes Payable		31,109		34,447
Navios Logistics BBVA Loan Facility		23,250		25,000
Navios Logistics Alpha Bank Loan		13,300		—
Navios Logistics Term Loan B Facility		100,000		—
Other long-term loans		253		321
Total Navios Logistics borrowings	$	542,912	$	434,768


Total	December 31, 2017		December 31, 2016
Total borrowings	$	1,717,768	$	1,675,415
Less: current portion, net		(33,885)		(29,827)
Less: deferred finance costs and discount, net		(35,280)		(24,320)
Total long-term borrowings	$	1,648,603	$	1,621,268

Principal payments


Payment due by period
September 30, 2019	$	34,840
September 30, 2020		73,216
September 30, 2021		56,817
September 30, 2022		1,426,583
September 30, 2023		33,042
September 30, 2024 and thereafter		4,087

Total	$	1,628,585


Year
2018	$	35,988
2019		33,326
2020		71,454
2021		154,825
2022		1,414,638
2023 and thereafter		7,537
Total	$	1,717,768

Fair Value of Financial Instruments (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2018

Dec. 31, 2017

FAIR VALUE OF FINANCIAL INSTRUMENTS [abstract]

Fair value of financial instruments


	September 30, 2018						December 31, 2017
	Book Value			Fair Value			Book Value			Fair Value
Cash and cash equivalents	$	132,925		$	132,925		$	127,632		$	127,632
Restricted cash	$	10,056		$	10,056		$	6,558		$	6,558
Loan receivable from affiliate companies	$	34,635		$	34,635		$	30,112		$	30,112
Investments in available-for-sale-securities	$	227		$	227		$	238		$	238
Senior and ship mortgage notes, net	$	(1,270,726	)	$	(1,112,673	)	$	(1,301,999	)	$	(1,181,838	)
Long-term debt, including current portion	$	(328,605	)	$	(335,301	)	$	(380,489	)	$	(389,332	)
Long term payable to affiliate companies	$	(86,005	)	$	(86,005	)	$	(76,872	)	$	(76,872	)

	December 31, 2017				December 31, 2016
	Book Value		Fair Value		Book Value		Fair Value
Cash and cash equivalents	$	127,632	$	127,632	$	135,992	$	135,992
Restricted cash	$	6,558	$	6,558	$	5,386	$	5,386
Investments in available-for-sale-securities	$	238	$	238	$	—	$	—
Loan receivable from affiliate companies	$	30,112	$	30,112	$	23,008	$	23,008
Long-term receivable from affiliate companies	$	—	$	—	$	11,105	$	11,105
Capital lease obligations, including current portion	$	—	$	—	$	(17,617)	$	(17,617)
Senior and ship mortgage notes, net	$	(1,301,999)	$	(1,181,838)	$	(1,296,537)	$	(974,170)
Long-term debt, including current portion	$	(380,489)	$	(389,332)	$	(304,682)	$	(308,080)
Loan payable to affiliate company	$	—	$	—	$	(49,876)	$	(51,240)
Long-term payable to affiliate companies	$	(76,872)	$	(76,872)	$	(6,399)	$	(6,399)

Fair value measurements on a recurring basis


	Fair Value Measurements as of September 30, 2018
	Total		Quoted Prices in Active Markets for Identical Assets (Level I)		Significant Other Observable Inputs (Level II)		Significant Unobservable Inputs (Level III)
Investments in available-for-sale-securities	$	227	$	227	$	—	$	—

Total	$	227	$	227	$	—	$	—


	Fair Value Measurements as of December 31, 2017
	Total		Quoted Prices in Active Markets for Identical Assets (Level I)		Significant Other Observable Inputs (Level II)		Significant Unobservable Inputs (Level III)
Investments in available-for-sale-securities	$	238	$	238	$	—	$	—

Total	$	238	$	238	$	—	$	—


	Fair Value Measurements as of December 31, 2017
	Total		Quoted Prices in Active Markets for Identical Assets (Level I)		Significant Other Observable Inputs (Level II)		Significant Unobservable Inputs (Level III)
Investments in available-for-sale-securities	$	238	$	238	$	—	$	—

Total	$	238	$	238	$	—	$	—

Fair value measurements on a nonrecurring basis


	Fair Value Measurements as of December 31, 2017
	Total		Quoted Prices in Active Markets for Identical Assets (Level I)		Significant Other Observable Inputs (Level II)		Significant Unobservable Inputs (Level III)
Vessels, port terminals and other fixed assets, net	$	16,500	$	—	$	16,500	$	—

Total	$	16,500	$	—	$	16,500	$	—


	Fair Value Measurements as of December 31, 2017
	Total		Quoted Prices in Active Markets for Identical Assets (Level I)		Significant Other Observable Inputs (Level II)		Significant Unobservable Inputs (Level III)
Vessels, port terminals and other fixed assets, net	$	16,500	$	—	$	16,500	$	—


	Fair Value Measurements as of December 31, 2016
	Total		Quoted Prices in Active Markets for Identical Assets (Level I)		Significant Other Observable Inputs (Level II)		Significant Unobservable Inputs (Level III)
Investments in affiliates	$	148,095	$	148,095	$	—	$	—

Fair value measurements on a nonrecurring basis


		Fair Value Measurements at September 30, 2018
		Total			(Level I)			(Level II)			(Level III)
Cash and cash equivalents		$	132,925		$	132,925		$	—		$	—
Restricted cash		$	10,056		$	10,056		$	—		$	—
Loan receivable from affiliate companies (2)		$	34,635		$	—		$	34,635		$	—
Senior and ship mortgage notes		$	(1,112,673	)	$	(1,112,673	)	$	—		$	—
Long-term debt, including current portion (1)		$	(335,301	)	$	—		$	(335,301	)	$	—
Long-term payable to affiliate companies (2)		$	(86,005	)	$	—		$	(86,005	)	$	—

		Fair Value Measurements at December 31, 2017
		Total			(Level I)			(Level II)			(Level III)
Cash and cash equivalents		$	127,632		$	127,632		$	—		$	—
Restricted cash		$	6,558		$	6,558		$	—		$	—
Loan receivable from affiliate companies (2)		$	30,112		$	—		$	30,112		$	—
Senior and ship mortgage notes		$	(1,181,838	)	$	(1,181,838	)	$	—		$	—
Long-term debt, including current portion (1)		$	(389,332	)	$	—		$	(389,332	)	$	—
Long-term payable to affiliate companies (2)		$	(76,872	)	$	—		$	(76,872	)	$	—
(1)	The fair value of the Company’s long-term debt is estimated based on currently available debt with similar contract terms, interest rates and remaining maturities, published quoted market prices as well as taking into account the Company’s creditworthiness.
(2)	The fair value of the Company’s loan receivable from/ payable to affiliate companies and long-term receivable from/payable to affiliate companies is estimated based on currently available debt with similar contract terms, interest rates and remaining maturities as well as taking into account the counterparty’s creditworthiness.


	Fair Value Measurements at December 31, 2017
	Total		(Level I)			(Level II)			(Level III)
Cash and cash equivalents	$	127,632		$	127,632		$	—		$	—
Restricted cash	$	6,558		$	6,558		$	—		$	—
Investments in available-for-sale-securities	$	238		$	238		$	—		$	—
Loan receivable from affiliate companies(2)	$	30,112		$	—		$	30,112		$	—
Senior and ship mortgage notes	$	(1,181,838)		$	(1,181,838)		$	—		$	—
Long-term debt, including current portion(1)	$	(389,332)		$	—		$	(389,332)		$	—
Long-term payable to affiliate companies(2)	$	(76,872)		$	—		$	(76,872)		$	—


	Fair Value Measurements at December 31, 2016
	Total		(Level I)		(Level II)		(Level III)
Cash and cash equivalents	$	135,992	$	135,992	$	—	$	—
Restricted cash	$	5,386	$	5,386	$	—	$	—
Loan receivable from affiliate company(2)	$	23,008	$	—	$	23,008	$	—
Long-term receivable from affiliate companies (2)	$	11,105	$	—	$	11,105	$	—
Capital lease obligations, including current portion (1)	$	(17,617)	$	—	$	(17,617)	$	—
Senior and ship mortgage notes	$	(974,170)	$	(974,170)	$	—	$	—
Long-term debt, including current portion(1)	$	(308,080)	$	—	$	(308,080)	$	—
Loan payable to affiliate company(2)	$	(51,240)	$	—	$	(51,240)	$	—
Long-term payable to affiliate companies(2)	$	(6,399)	$	—	$	(6,399)	$	—

(1)	The fair value of the Company’s long-term debt/ Capital lease obligations is estimated based on currently available debt with similar contract terms, interest rates and remaining maturities, published quoted market prices as well as taking into account the Company’s creditworthiness.
(2)	The fair value of the Company’s loan receivable from/ payable to affiliate companies and long-term receivable from/payable to affiliate companies is estimated based on currently available debt with similar contract terms, interest rate and remaining maturities as well as taking into account the counterparty’s creditworthiness.

Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2017

EMPLOYEE BENEFIT PLANS [Abstract]

Summary of stock based awards


	Shares			Weighted average exercise price		Weighted average remaining term		Aggregate fair value
Options
Outstanding as of December 31, 2014		5,804,594		$	4.57		4.64	$	8,410
Vested at December 31, 2014		1,643,665			—		—		—
Exercisable at December 31, 2014		1,500,476			—		—		—
Forfeited or expired		(159,828	)		—		—		(193	)
Granted		1,000,000			1.2		—		552
Outstanding as of December 31, 2015		6,644,766		$	4.09		4.23	$	8,769
Vested at December 31, 2015		730,592			—		—		—
Exercisable at December 31, 2015		730,592			—		—		—
Forfeited or expired		(348,520	)		—		—		—
Granted		2,500,000			1.2		—		—
Outstanding as of December 31, 2016		8,796,246		$	3.20		4.41	$	9,804
Vested at December 31, 2016		1,210,824			—		—		—
Exercisable at December 31, 2016		1,210,824			—		—		—
Forfeited or expired		(891,670)			—		—		—
Granted		—			—		—		—
Outstanding as of December 31, 2017		7,904,576		$	2.98		3.80	$	7,539
Restricted stock and restricted stock units
Non Vested as of December 31, 2014		1,997,344		$	—		2.00	$	10,899
Granted		2,540,000			—		—		3,048
Vested		(812,847	)		—		—		(5,746	)
Forfeited or expired		(3,538	)		—		—		(15	)
Non Vested as of December 31, 2015		3,720,959		$	—		2.45	$	8,186
Granted		2,540,000			—		—		3,048
Vested		(1,755,017	)		—		—		(5,122	)
Forfeited or expired		(3,408	)		—		—		(12	)
Non Vested as of December 31, 2016		4,502,534		$	—		2.55	$	6,100
Granted		4,353,975			—		—		42
Vested		(1,839,195)			—		—		(2,630	)
Forfeited or expired		—			—		—		—
Non Vested as of December 31, 2017		7,017,314		$	—		3.21	$	3,512

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2018

COMMITMENTS AND CONTINGENCIES [Abstract]

Future minimum contractual obligations


	Charter-in Vessels, barges and pushboats in operation		Charter-in vessels to be delivered
September 30, 2019	$	116,882	$	6,674
September 30, 2020		104,591		15,226
September 30, 2021		76,120		17,080
September 30, 2022		48,112		16,883
September 30, 2023		37,640		16,463
September 30, 2024 and thereafter		50,350		49,683

Total	$	433,695	$	122,009

Leases (Tables)

12 Months Ended

Dec. 31, 2017

LEASES [Abstract]

Chartered-in vessels, barges, pushboats and office space


	Charter-in vessels in operation		Charter-in vessels to be delivered			Office space
2018	$	119,023	$	8,725	$		1,992
2019		96,048		19,316			1,314
2020		82,638		20,945			509
2021		63,040		10,807			184
2022		43,689		10,109			—
2023 and thereafter		77,828		19,371			—
Total	$	482,266	$	89,273	$		3,999

Chartered-out vessels, barges and pushboats


	Dry bulk vessels		Logistics business
2018	$	35,420	$	138,384
2019		2,458		104,721
2020		—		77,209
2021		—		62,290
2022		—		55,450
2023 and thereafter		—		699,388
Total minimum revenue, net of commissions	$	37,878	$	1,137,442

Interest Expense and Finance Cost (Tables)

12 Months Ended

Dec. 31, 2017

INTEREST EXPENSE AND FINANCE COST [Abstract]

Interest expense and finance cost


	For the Year Ended December 31, 2017		For the Year Ended December 31, 2016		For the Year Ended December 31, 2015
Interest expense	$	115,099	$	107,787	$	108,488
Amortization and write-off of deferred financing costs		6,391		5,653		4,524
Other		121		199		139
Interest expense and finance cost	$	121,611	$	113,639	$	113,151

Segment Information (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2018

Dec. 31, 2017

SEGMENT INFORMATION [Abstract]

Segment summarized financial information


	Drybulk Vessel Operations						Logistics Business						Total
	Three Month Period Ended September 30, 2018			Three Month Period Ended September 30, 2017			Three Month Period Ended September 30, 2018			Three Month Period Ended September 30, 2017			Three Month Period Ended September 30, 2018			Three Month Period Ended September 30, 2017
Revenue	$	85,533		$	60,976		$	55,920		$	59,579		$	141,453		$	120,555
Administrative fee revenue from affiliates		7,357			6,284			—			—			7,357			6,284
Interest expense and finance cost, net		(22,778	)		(21,379	)		(9,956	)		(7,446	)		(32,734	)		(28,825	)
Depreciation and amortization		(17,389	)		(19,023	)		(7,255	)		(7,156	)		(24,644	)		(26,179	)
Equity in net (losses)/earnings of affiliated companies		(4,231	)		901			—			—			(4,231	)		901
Net (loss)/income attributable to Navios Holdings common stockholders		(6,111	)		(29,509	)		4,295			1,177			(1,816	)		(28,332	)
Total assets		1,806,177			1,996,951			682,680			663,656			2,488,857			2,660,607
Goodwill		56,240			56,240			104,096			104,096			160,336			160,336
Capital expenditures		(1,301	)		(161	)		(10,083	)		(7,234	)		(11,384	)		(7,395	)
Investments in affiliates		166,888			185,548			—			—			166,888			185,548
Cash and cash equivalents		50,378			46,155			82,547			68,043			132,925			114,198
Restricted cash		10,056			5,040			—			—			10,056			5,040
Long-term debt (including current and non-current portion)	$	1,066,080		$	1,204,234		$	533,251		$	438,981		$	1,599,331		$	1,643,215

	Drybulk Vessel Operations						Logistics Business						Total
	Nine Month Period Ended September 30, 2018			Nine Month Period Ended September 30, 2017			Nine Month Period Ended September 30, 2018			Nine Month Period Ended September 30, 2017			Nine Month Period Ended September 30, 2018			Nine Month Period Ended September 30, 2017
Revenue	$	222,135		$	171,758		$	168,251		$	162,761		$	390,386		$	334,519
Administrative fee revenue from affiliates		21,488			16,942			—			—			21,488			16,942
Interest expense and finance cost, net		(68,599	)		(64,290	)		(29,198	)		(19,522	)		(97,797	)		(83,812	)
Depreciation and amortization		(53,612	)		(58,269	)		(21,635	)		(19,624	)		(75,247	)		(77,893	)
Equity in net (losses)/earnings of affiliated companies		(13,720	)		2,208			—			—			(13,720	)		2,208
Net (loss)/income attributable to Navios Holdings common stockholders		(74,141	)		(116,394	)		6,176			2,085			(67,965	)		(114,309	)
Total assets		1,806,177			1,996,951			682,680			663,656			2,488,857			2,660,607
Goodwill		56,240			56,240			104,096			104,096			160,336			160,336
Capital expenditures		(13,747	)		(261	)		(16,129	)		(36,304	)		(29,876	)		(36,565	)
Investments in affiliates		166,888			185,548			—			—			166,888			185,548
Cash and cash equivalents		50,378			46,155			82,547			68,043			132,925			114,198
Restricted cash		10,056			5,040			—			—			10,056			5,040
Long-term debt (including current and non-current portion)	$	1,066,080		$	1,204,234		$	533,251		$	438,981		$	1,599,331		$	1,643,215


	Dry Bulk Vessel Operations for the Year Ended December 31, 2017		Logistics Business for the Year Ended December 31, 2017		Total for the Year Ended December 31, 2017
Revenue	$	250,433	$	212,616	$	463,049
Administrative fee revenue from affiliates		23,667		—		23,667
Interest income		6,593		238		6,831
Interest expense and finance cost		(93,264)		(28,347)		(121,611)
Depreciation and amortization		(77,245)		(26,867)		(104,112)
Equity/ (Loss) in net earnings of affiliated companies		4,399		—		4,399
Net (loss)/ income attributable to Navios Holdings common stockholders		(167,892)		1,982		(165,910)
Total assets		1,947,777		682,204		2,629,981
Goodwill		56,240		104,096		160,336
Capital expenditures		(347)		(46,521)		(46,868)
Investment in affiliates		183,160		—		183,160
Cash and cash equivalents		47,744		79,888		127,632
Restricted cash		6,558		—		6,558
Long-term debt, net (including current and noncurrent portion)	$	1,149,742	$	532,746	$	1,682,488


	Dry Bulk Vessel Operations for the Year Ended December 31, 2016		Logistics Business for the Year Ended December 31, 2016		Total for the Year Ended December 31, 2016
Revenue	$	199,446	$	220,336	$	419,782
Administrative fee revenue from affiliates		21,799		—		21,799
Interest income		4,132		815		4,947
Interest expense and finance cost		(89,399)		(24,240)		(113,639)
Depreciation and amortization		(87,197)		(26,628)		(113,825)
Equity/ (Loss) in net earnings of affiliated companies		(202,779)		—		(202,779)
Net (loss)/ income attributable to Navios Holdings common stockholders		(310,306)		6,483		(303,823)
Total assets		2,083,526		669,369		2,752,895
Goodwill		56,240		104,096		160,336
Capital expenditures		(60,420)		(91,173)		(151,593)
Investment in affiliates		160,071		—		160,071
Cash and cash equivalents		70,810		65,182		135,992
Restricted cash		2,486		2,900		5,386
Long-term debt, net (including current and noncurrent portion)	$	1,223,146	$	427,949	$	1,651,095


	Dry Bulk Vessel Operations for the Year Ended December 31, 2015		Logistics Business for the Year Ended December 31, 2015		Total for the Year Ended December 31, 2015
Revenue	$	229,772	$	251,048	$	480,820
Administrative fee revenue from affiliates		16,177		—		16,177
Interest income		1,801		569		2,370
Interest expense and finance cost		(86,069)		(27,082)		(113,151)
Depreciation and amortization		(92,341)		(27,969)		(120,310)
Equity in net earnings of affiliated companies		61,484		—		61,484
Net (loss)/ income attributable to Navios Holdings common stockholders		(148,306)		14,194		(134,112)
Total assets		2,359,299		599,514		2,958,813
Goodwill		56,240		104,096		160,336
Capital expenditures		(7,882)		(27,039)		(34,921)
Investment in affiliates		381,746		—		381,746
Cash and cash equivalents		81,905		81,507		163,412
Restricted cash		13,480		—		13,480
Long-term debt, net (including current and noncurrent portion)	$	1,213,740	$	367,568	$	1,581,308

Revenue by geographic region


	Year ended December 31, 2017		Year ended December 31, 2016		Year ended December 31, 2015
North America	$	5,513	$	6,218	$	22,317
Europe		124,857		109,267		109,347
Asia		91,552		73,073		87,658
South America		212,616		220,336		253,746
Other		28,511		10,888		7,752
Total	$	463,049	$	419,782	$	480,820

Loss Per Common Share (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2018

Dec. 31, 2017

LOSS PER COMMON SHARE [Abstract]

Loss per common share


	Three Month Period Ended September 30, 2018			Three Month Period Ended September 30, 2017			Nine Month Period Ended September 30, 2018			Nine Month Period Ended September 30, 2017
Numerator:
Net loss attributable to Navios Holdings common stockholders	$	(1,816	)	$	(28,332	)	$	(67,965	)	$	(114,309	)
Less:
Declared and undeclared dividend on preferred stock and on unvested restricted shares		(2,566	)		(2,555	)		(7,679	)		(7,859	)
Plus:
Tender Offer – Redemption of preferred stock Series G and Series H including $702 and $972 of undeclared preferred dividend cancelled for the three and nine months of 2017, respectively		—			615			—			1,119

Loss attributable to Navios Holdings common stockholders, basic and diluted	$	(4,382	)	$	(30,272	)	$	(75,644	)	$	(121,049	)

Denominator:
Denominator for basic and diluted net loss per share attributable to Navios Holdings common stockholders — weighted average shares		119,423,135			117,535,234			119,423,025			116,260,640

Basic and diluted net losses per share attributable to Navios Holdings common stockholders	$	(0.04	)	$	(0.26	)	$	(0.63	)	$	(1.04	)


	Year ended December 31, 2017		Year ended December 31, 2016		Year ended December 31, 2015
Numerator:
Net loss attributable to Navios Holdings common stockholders	$	(165,910)	$	(303,823)	$	(134,112)
Declared and undeclared dividend on preferred stock and on unvested restricted shares		(10,421)		(15,909)		(16,202)
Tender Offer – Redemption of preferred stock Series G and H including $972 and $5,063 of undeclared preferred dividend cancelled for the year ended December 31, 2017 and December 31, 2016, respectively		1,033		46,627		—
Loss available to Navios Holdings common stockholders, basic and diluted	$	(175,298)	$	(273,105)	$	(150,314)

Denominator:
Denominator for basic and diluted net loss per share attributable to Navios Holdings stockholders — adjusted weighted shares		116,673,459		107,366,783		105,896,235

Basic and diluted net loss per share attributable to Navios Holdings stockholders	$	(1.50)	$	(2.54)	$	(1.42)

Investment in affiliates and available-for-sale securities (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2018

Dec. 31, 2017

INVESTMENTS IN AFFILIATES AND INVESTMENTS IN AVAILABLE-FOR-SALE SECURITIES [Abstract]

Financial information of affiliate companies, balance sheet


	September 30, 2018				December 31, 2017
	Navios Partners		Navios Acquisition		Navios Partners		Navios Acquisition
Balance Sheet
Cash and cash equivalents, including restricted cash	$	58,322	$	48,313	$	29,933	$	86,458
Current assets		89,350		90,536		60,306		119,733
Non-current assets		1,239,273		1,365,936		1,244,996		1,453,048
Current liabilities		54,075		136,826		54,247		74,618
Long- term debt including current portion, net		511,669		1,016,324		493,463		1,065,369
Non-current liabilities		491,262		941,694		483,345		1,035,688


	December 31, 2017								December 31, 2016
Balance Sheet	Navios Partners		Navios Europe I		Navios Europe II		Navios Containers		Navios Partners		Navios Europe I		Navios Europe II
Cash and cash equivalents, including restricted cash	$	29,933	$	19,185	$	16,882	$	14,501	$	25,088	$	10,785	$	16,916
Current assets		60,306		22,417		28,403		21,371		56,349		15,980		19,487
Non-current assets		1,244,996		145,940		195,784		245,440		1,212,231		169,925		232,363
Current liabilities		54,247		21,284		25,805		49,559		98,950		18,490		24,126
Long- term debt including current portion, net		493,463		75,472		109,223		119,033		523,776		86,060		119,234
Non-current liabilities		483,345		125,283		164,276		76,534		489,421		155,387		184,530

Financial information of affiliate companies, income statement

	Nine Month Period Ended September 30, 2018						Nine Month Period Ended September 30, 2017
	Navios Partners			Navios Acquisition			Navios Partners		Navios Acquisition
Income Statement
Revenue	$	173,819		$	129,218		$	152,383	$	176,961
Net (loss)/ income	$	(13,598	)	$	(69,942	)	$	7,965	$	(66,907	)

	Three Month Period Ended September 30, 2018						Three Month Period Ended September 30, 2017
	Navios Partners			Navios Acquisition			Navios Partners		Navios Acquisition
Income Statement
Revenue	$	62,571		$	41,589		$	59,954	$	54,021
Net income / (loss)	$	10,457		$	(23,408	)	$	9,173	$	(8,105	)


	December 31, 2017												December 31, 2016									December 31, 2015
Income Statement	Navios Partners		Navios Europe I			Navios Europe II			Navios Containers			Navios Partners			Navios Europe I			Navios Europe II			Navios Partners					Navios Europe I			Navios Europe II
Revenue	$	211,652		$	37,468		$	38,633		$	39,188		$	190,524		$	40,589		$	30,893			$	223,676	$		41,437	$		20,767
Net (loss)/ income before non-cash change in fair value of Junior Loan I and Junior Loan II	$	(15,090)		$	(20,778)		$	22,749		$	2,638		$	(52,549)		$	(2,174)		$	(25,062)			$	41,805	$		(1,347)	$		1,673
Net (loss)/income	$	(15,090)		$	9,762		$	(9,086)		$	2,638		$	(52,549)		$	16,137		$	(34,059)			$	41,805	$		(1,118)	$		77,252

Description of Business (Details) - USD ($) $ in Thousands	5 Months Ended	9 Months Ended	12 Months Ended
Description of Business (Details) - USD ($) $ in Thousands	Jun. 08, 2017	Sep. 30, 2018	Dec. 31, 2017
Subsidiary or Equity Method Investee [Line Items]
Trading Symbol		NM
Navios Logistics
Subsidiary or Equity Method Investee [Line Items]
Ownership percentage of Navios Holdings			63.80%
Navios Logistics
Subsidiary or Equity Method Investee [Line Items]
Ownership percentage of Navios Holdings		63.80%
Navios Partners
Subsidiary or Equity Method Investee [Line Items]
Ownership percentage of Navios Holdings		20.20%	20.80%
General partner interest of Navios Holdings		2.00%	2.00%
Trading Symbol		NMM
Navios Acquisition
Subsidiary or Equity Method Investee [Line Items]
Ownership percentage of Navios Holdings		48.60%	46.20%
Percentage of voting stock of Navios Holdings in Navios Acquisition		45.30%	42.90%
Trading Symbol		NNA
Share repurchase program, Authorized amount		$ 25,000
Number of stocks repurchased		8,055,074
Navios Midstream
Subsidiary or Equity Method Investee [Line Items]
Ownership percentage of Navios Holdings		0.00%	0.00%
Trading Symbol		NAP
Navios Containers
Subsidiary or Equity Method Investee [Line Items]
Ownership percentage of Navios Holdings		3.10%	3.40%
Trading Symbol		NMCI
Navios Acquisition
Subsidiary or Equity Method Investee [Line Items]
Ownership percentage of Navios Holdings		48.60%	46.20%
Percentage of voting stock of Navios Holdings in Navios Acquisition			42.90%
Private placement \| Navios Containers
Subsidiary or Equity Method Investee [Line Items]
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	$ 5,000
Warrants \| Navios Containers
Subsidiary or Equity Method Investee [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners		1.70%	1.70%

Description of Business - Related Parties - Navios Europe I and Navios Europe II (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Feb. 18, 2015	Oct. 09, 2013
Navios Europe I
Related Party Transaction [Line Items]
Percentage of ownership	47.50%
Navios Europe I \| Navios Holdings
Related Party Transaction [Line Items]
Percentage of ownership				47.50%
Percentage of voting stock held	50.00%	50.00%
Navios Europe I \| Navios Acquisition
Related Party Transaction [Line Items]
Percentage of ownership				47.50%
Percentage of voting stock held	50.00%	50.00%
Navios Europe I \| Navios Partners
Related Party Transaction [Line Items]
Percentage of ownership				5.00%
Percentage of voting stock held	0.00%	0.00%
Navios Europe I \| Container vessels
Related Party Transaction [Line Items]
Number of vessels	5	5
Navios Europe I \| Tanker vessels
Related Party Transaction [Line Items]
Number of vessels	5	5
Navios Europe II
Related Party Transaction [Line Items]
Percentage of ownership	47.50%
Navios Europe II \| Navios Holdings
Related Party Transaction [Line Items]
Percentage of ownership			47.50%
Percentage of voting stock held	50.00%	50.00%
Navios Europe II \| Navios Acquisition
Related Party Transaction [Line Items]
Percentage of ownership			47.50%
Percentage of voting stock held	50.00%	50.00%
Navios Europe II \| Navios Partners
Related Party Transaction [Line Items]
Percentage of ownership			5.00%
Percentage of voting stock held	0.00%	0.00%
Navios Europe II \| Dry bulkers vessels
Related Party Transaction [Line Items]
Number of vessels	7	7
Navios Europe II \| Container vessels
Related Party Transaction [Line Items]
Number of vessels	7	7

Summary of Significant Accounting Policies - Subsidiaries (Table) (Details)	12 Months Ended
	Dec. 31, 2017
Navios Maritime Holdings Inc.
Entity Information [Line Items]
Nature	Holding Company
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios Corporation
Entity Information [Line Items]
Nature	Sub-Holding Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios International Inc.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navimax Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios Handybulk Inc.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Hestia Shipping Ltd.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Anemos Maritime Holdings Inc.
Entity Information [Line Items]
Nature	Sub-Holding Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios Shipmanagement Inc.
Entity Information [Line Items]
Nature	Management Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
NAV Holdings Limited
Entity Information [Line Items]
Nature	Sub-Holding Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Kleimar N.V.
Entity Information [Line Items]
Nature	Operating Company/Vessel Owning Company/Management Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Kleimar Ltd.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Bulkinvest S.A.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Primavera Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Ginger Services Co.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Aquis Marine Corp.
Entity Information [Line Items]
Nature	Sub-Holding Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios Tankers Management Inc.
Entity Information [Line Items]
Nature	Management Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Astra Maritime Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Achilles Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Apollon Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Herakles Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Hios Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Ionian Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Kypros Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Meridian Shipping Enterprises Inc.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Mercator Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Arc Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Horizon Shipping Enterprises Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Magellan Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Aegean Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Star Maritime Enterprises Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Corsair Shipping Ltd.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Rowboat Marine Inc.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Beaufiks Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Nostos Shipmanagement Corp.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Portorosa Marine Corp.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Shikhar Ventures S.A.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Sizzling Ventures Inc.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Rheia Associates Co.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Taharqa Spirit Corp.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Rumer Holding Ltd.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Pharos Navigation S.A.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Pueblo Holdings Ltd.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Quena Shipmanagement Inc.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Aramis Navigation Inc.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
White Narcissus Marine S.A.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios GP L.L.C.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Red Rose Shipping Corp.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Highbird Management Inc.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Ducale Marine Inc.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Vector Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Faith Marine Ltd.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios Maritime Finance (US) Inc.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios Maritime Finance II (US) Inc.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Tulsi Shipmanagement Co.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Cinthara Shipping Ltd.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Rawlin Services Company
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Mauve International S.A.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Serenity Shipping Enterprises Inc.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Mandora Shipping Ltd.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Solange Shipping Ltd.
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Diesis Ship Management Ltd.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios Holdings Europe Finance Inc.
Entity Information [Line Items]
Nature	Sub-Holding Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Navios Asia LLC
Entity Information [Line Items]
Nature	Sub-Holding Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Iris Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Jasmine Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Emery Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Lavender Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	1/1 - 12/31
Esmeralda Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/12 - 12/31
Triangle Shipping Corporation
Entity Information [Line Items]
Nature	Vessel Owning Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/12 - 12/31
Roselite Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	10/9 - 12/31
Smaltite Shipping Corporation
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	1/1 - 12/31
2016	10/9 - 12/31
Motiva Trading Ltd
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	1/1 - 12/31
2017	11/2 - 12/31
Alpha Merit Corporation
Entity Information [Line Items]
Nature	Sub-Holding Company
Ownership Interest	100.00%
Statement of Operations
2018	11/3 - 12/31
Thalassa Marine S.A.
Entity Information [Line Items]
Nature	Operating Company
Ownership Interest	100.00%
Statement of Operations
2018	12/15 - 12/31

Summary of Significant Accounting Policies - Depreciation Periods (Table) (Details)	12 Months Ended
	Dec. 31, 2017
Vessels
Property Plant And Equipment [Line Items]
Useful life assets	25 years
Port terminals \| Minimum
Property Plant And Equipment [Line Items]
Useful life assets	5 years
Port terminals \| Maximum
Property Plant And Equipment [Line Items]
Useful life assets	40 years
Tanker vessels, barges and pushboats \| Minimum
Property Plant And Equipment [Line Items]
Useful life assets	15 years
Tanker vessels, barges and pushboats \| Maximum
Property Plant And Equipment [Line Items]
Useful life assets	45 years
Furniture, fixtures and equipment \| Minimum
Property Plant And Equipment [Line Items]
Useful life assets	3 years
Furniture, fixtures and equipment \| Maximum
Property Plant And Equipment [Line Items]
Useful life assets	10 years
Computer equipment and software
Property Plant And Equipment [Line Items]
Useful life assets	5 years
Leasehold improvements
Property Plant And Equipment [Line Items]
Useful life assets	shorter of lease term or 6 years

Summary of Significant Accounting Policies - Amortization Periods (Table) (Details)	12 Months Ended
	Dec. 31, 2017
Trade name
Acquired Finite Lived Intangible Assets
Weighted average amortization periods	30 years
Favorable lease terms
Acquired Finite Lived Intangible Assets
Weighted average amortization periods	8 years
Port terminal operating rights
Acquired Finite Lived Intangible Assets
Weighted average amortization periods	47 years
Customer relationships
Acquired Finite Lived Intangible Assets
Weighted average amortization periods	20 years

Summary of Significant Account Policies, Restricted Cash (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
RESTRICTED CASH AND CASH EQUIVALENTS [ABSTRACT]
Cash and cash equivalents	$ 132,925	$ 127,632	$ 114,198	$ 135,992	$ 163,412	$ 247,556
Restricted cash	10,056	6,558	5,040	5,386	$ 13,480
Total cash and cash equivalents and restricted cash	$ 142,981	$ 134,190	$ 119,238	$ 141,377

Summary of Significant Accounting Policies - Basis Of Presentation, Subsidiaries, Affiliates and Restricted Cash (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase/(decrease) in cash and cash equivalents			$ (8,360)	$ (27,420)	$ (84,144)
Restricted cash	$ 10,056	$ 5,040	$ 6,558	5,386	$ 13,480
Navios Logistics
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Ownership percentage of Navios Holdings			63.80%
Letter of Credit \| Navios Logistics
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash				2,900
Retention Accounts
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash			$ 5,968	1,896
Amount Held as Security
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash			$ 590	$ 590
Navios Logistics
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Ownership percentage of Navios Holdings	63.80%
Navios Partners and its subsidiaries
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Economic interest	20.20%		20.80%
General partner interest of Navios Holdings	2.00%		2.00%
Navios Acquisition and its subsidiaries
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Economic interest	48.60%		46.20%
Acropolis Chartering and Shipping Inc. ("Acropolis")
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Economic interest	35.00%		35.00%
Ownership percentage of Navios Holdings	50.00%		50.00%
Navios Europe I and its subsidiaries
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Economic interest	47.50%
Navios Europe II and its subsidiaries
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Economic interest	47.50%
Navios Containers and its subsidiaries
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Economic interest	3.10%		3.40%
Effect of retrospective application
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase/ (decrease) in net cash provided by operating activities		(2,836)
Increase/ (decrease) in net cash provided financing activities		(2,491)
Increase/(decrease) in cash and cash equivalents		$ (345)

Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	$ 141,453	$ 120,555	$ 390,386	$ 334,519	$ 463,049	$ 419,782	$ 480,820
Paraguay \| Logistics business \| Sale of Products
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	6,191	8,964	23,881	25,786
Contracts of Affreightment ("COA")/ Voyage Contracts \| Dry Bulk Vessel Operations
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	3,275	8,159	17,892	27,447
Contracts of Affreightment ("COA")/ Voyage Contracts \| Logistics business
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	10,655	11,232	30,207	34,683
Time and bareboat chartering \| Dry Bulk Vessel Operations
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	82,007	50,408	204,168	134,133
Time and bareboat chartering \| Logistics business
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	19,790	24,804	56,324	66,154
Pooling arrangements
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue					$ 8,041	$ 15,115	$ 1,825
Pooling arrangements \| Dry Bulk Vessel Operations
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	0	1,087	0	8,219
Profit Sharing \| Dry Bulk Vessel Operations
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	153	759	(52)	1,205
Port Terminal Operations \| Logistics business
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	17,257	11,819	51,848	29,428
Storage Fees (dry port) \| Logistics business
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	185	285	526	984
Dry Port Terminal Operations \| Logistics business
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	697	1,728	2,227	3,582
Liquid Port Terminal Operations \| Paraguay \| Logistics business
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue	$ 963	$ 707	$ 2,821	$ 1,990

Accounts Receivable, Net - Provisions For Doubtful Accounts (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
ACCOUNTS RECEIVABLE,NET [Abstract]
Balance at Beginning of Period	$ (19,437)	$ (18,278)	$ (18,464)
Charges to Costs and Expenses	(269)	(1,304)	(59)
Amount Utilized	0	145	245
Balance at End of Period	$ (19,706)	$ (19,437)	$ (18,278)

Accounts Receivable, Net (Details)	12 Months Ended
Accounts Receivable, Net (Details)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Concentration of credit risk with respect to accounts receivable	Concentration of credit risk with respect to accounts receivable is limited due to the Company's large number of customers, who are internationally dispersed and have a variety of end markets in which they sell. Due to these factors, management believes that no additional credit risk beyond amounts provided for collection losses is inherent in the Company's trade receivables.
Customer 1
Loss Contingencies [Line Items]
Concentration Risk, Percentage	0.00%	14.70%	15.10%
Customer 2
Loss Contingencies [Line Items]
Concentration Risk, Percentage	0.00%	13.10%

Vessels, Port Terminal and Other Fixed Assets, Net (Table) (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Balance	$ 1,809,225	$ 1,821,101	$ 1,821,101
Additions	(64,569)
Impairment losses	(15,004)
Vessel disposals	(94,767)
Other disposals	(19)
Write offs	(34)		50,565	$ 0	$ 0
Vessel acquisition	10,202
Revaluation of vessels due to termination of capital lease obligation	0	5,243	5,243	0	210
Transfers from deposits for vessels, port terminal and other fixed assets	49,421	137,357	137,357	0	0
Transfers to other long term-assets	(26)	0
Balance	1,694,429		1,809,225	1,821,101
Cost
Property Plant And Equipment [Line Items]
Balance	2,553,047	2,529,488	2,529,488	2,434,639	2,425,931
Additions	6,493		11,122	65,154	8,918
Impairment losses	(59,003)		(104,157)
Vessel disposals	(94,767)		(15,488)
Other disposals	(156)
Write offs	(55)		(32)
Vessel acquisition	10,255
Restructure of capital lease					(210)
Revaluation of vessels due to termination of capital lease obligation			(5,243)
Transfers from deposits for vessels, port terminal and other fixed assets	49,421		137,357	29,695
Transfers to other long term-assets	(26)
Balance	2,465,209		2,553,047	2,529,488	2,434,639
Cost \| Vessels
Property Plant And Equipment [Line Items]
Balance	1,814,965	1,930,950	1,930,950	1,841,140	1,841,140
Additions				60,115
Impairment losses			(104,157)
Vessel disposals			(11,828)
Transfers from deposits for vessels, port terminal and other fixed assets				29,695
Balance			1,814,965	1,930,950	1,841,140
Cost \| Port Terminals (Navios Logistics)
Property Plant And Equipment [Line Items]
Balance	251,641	109,224	109,224	108,686	106,399
Additions			5,060	2,051	2,287
Transfers from deposits for vessels, port terminal and other fixed assets			137,357	(1,513)
Balance			251,641	109,224	108,686
Cost \| Tanker vessels, barges and pushboats (Navios Logistics)
Property Plant And Equipment [Line Items]
Balance	472,081	475,378	475,378	470,944	464,966
Additions			5,531	738	6,188
Vessel disposals			(3,585)
Restructure of capital lease					(210)
Revaluation of vessels due to termination of capital lease obligation			(5,243)
Transfers from deposits for vessels, port terminal and other fixed assets				3,696
Balance			472,081	475,378	470,944
Cost \| Other fixed assets
Property Plant And Equipment [Line Items]
Balance	14,360	13,936	13,936	13,869	13,426
Additions			531	2,250	443
Vessel disposals			(75)
Write offs			(32)
Transfers from deposits for vessels, port terminal and other fixed assets				(2,183)
Balance			14,360	13,936	13,869
Accumulated Depreciation
Property Plant And Equipment [Line Items]
Balance	(743,822)	(708,387)	(708,387)	(610,678)	(514,788)
Additions	(71,062)		(97,114)	(97,709)	(95,890)
Impairment losses	43,999		58,034
Vessel disposals			3,613
Other disposals	137
Write offs	21
Write offs			32
Vessel acquisition	(53)
Balance	(770,780)		(743,822)	(708,387)	(610,678)
Accumulated Depreciation \| Vessels
Property Plant And Equipment [Line Items]
Balance	(536,518)	(521,535)	(521,535)	(447,688)	(376,794)
Additions			(73,017)	(73,847)	(70,894)
Impairment losses			58,034
Balance			(536,518)	(521,535)	(447,688)
Accumulated Depreciation \| Port Terminals (Navios Logistics)
Property Plant And Equipment [Line Items]
Balance	(32,628)	(27,391)	(27,391)	(23,898)	(20,467)
Additions			(5,237)	(3,493)	(3,431)
Balance			(32,628)	(27,391)	(23,898)
Accumulated Depreciation \| Tanker vessels, barges and pushboats (Navios Logistics)
Property Plant And Equipment [Line Items]
Balance	(164,056)	(150,038)	(150,038)	(131,144)	(111,137)
Additions			(17,603)	(18,894)	(20,007)
Vessel disposals			3,585
Balance			(164,056)	(150,038)	(131,144)
Accumulated Depreciation \| Other fixed assets
Property Plant And Equipment [Line Items]
Balance	(10,620)	(9,423)	(9,423)	(7,948)	(6,390)
Additions			(1,257)	(1,475)	(1,558)
Vessel disposals			28
Write offs			32
Balance			(10,620)	(9,423)	(7,948)
Net Book Value
Property Plant And Equipment [Line Items]
Balance	1,809,225	1,821,101	1,821,101	1,823,961	1,911,143
Additions	(64,569)		(85,992)	(32,555)	(86,972)
Impairment losses	(15,004)		(46,123)
Vessel disposals	(94,767)		(11,875)
Other disposals	(19)
Write offs	(34)
Vessel acquisition	10,202
Restructure of capital lease					(210)
Revaluation of vessels due to termination of capital lease obligation			(5,243)
Transfers from deposits for vessels, port terminal and other fixed assets	49,421		137,357	29,695
Transfers to other long term-assets	(26)
Balance	1,694,429		1,809,225	1,821,101	1,823,961
Net Book Value \| Vessels
Property Plant And Equipment [Line Items]
Balance	1,278,447	1,409,415	1,409,415	1,393,452	1,464,346
Additions			(73,017)	(13,732)	(70,894)
Impairment losses			(46,123)
Vessel disposals			(11,828)
Transfers from deposits for vessels, port terminal and other fixed assets				29,695
Balance			1,278,447	1,409,415	1,393,452
Net Book Value \| Port Terminals (Navios Logistics)
Property Plant And Equipment [Line Items]
Balance	219,013	81,833	81,833	84,788	85,932
Additions			(177)	(1,442)	(1,144)
Transfers from deposits for vessels, port terminal and other fixed assets			137,357	(1,513)
Balance			219,013	81,833	84,788
Net Book Value \| Tanker vessels, barges and pushboats (Navios Logistics)
Property Plant And Equipment [Line Items]
Balance	308,025	325,340	325,340	339,800	353,829
Additions			(12,072)	(18,156)	(13,819)
Restructure of capital lease					(210)
Revaluation of vessels due to termination of capital lease obligation			(5,243)
Transfers from deposits for vessels, port terminal and other fixed assets				3,696
Balance			308,025	325,340	339,800
Net Book Value \| Other fixed assets
Property Plant And Equipment [Line Items]
Balance	$ 3,740	$ 4,513	4,513	5,921	7,036
Additions				775
Additions			(726)		(1,115)
Vessel disposals			(47)
Transfers from deposits for vessels, port terminal and other fixed assets				(2,183)
Balance			$ 3,740	$ 4,513	$ 5,921

Vessels, Port Terminal and Other Fixed Assets, Net (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 12, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 31, 2018	Jul. 31, 2018	Mar. 31, 2018	Jul. 13, 2017	Jun. 16, 2017	Mar. 31, 2016
Property Plant And Equipment [Line Items]
Cash consideration for purchase of vessel				$ 10,647	$ 0	$ 0	$ 60,115	$ 0
Impairment loss				(34)		$ 50,565	0	$ 0
Vessel impairment loss		$ 2,760	$ 0	$ 16,070	$ 14,239
Navios Primavera
Property Plant And Equipment [Line Items]
Year Built				2007
Vessel capacity in DWT				53,464 dwt
Deposit upon signing of contract				$ 1,063
Navios Mars
Property Plant And Equipment [Line Items]
Date of delivery						Jan. 12, 2016
Year Built						2016
Date of delivery						Jan. 12, 2016
Vessel capacity in DWT						181,259 dwt
Vessel acquisition cost	$ 55,458
Navios Mars \| Navios Partners
Property Plant And Equipment [Line Items]
Year Built				2016
Vessel capacity in DWT				181,259 dwt
Navios Sphera
Property Plant And Equipment [Line Items]
Date of delivery						Jan. 12, 2016
Year Built						2016
Vessel capacity in DWT						84,872 dwt
Vessel acquisition cost	34,352
Navios Sphera \| Navios Partners
Property Plant And Equipment [Line Items]
Year Built				2016
Vessel capacity in DWT				84,872 dwt
Navios Sphera and Navios Mars
Property Plant And Equipment [Line Items]
Cash consideration for purchase of vessel	49,910
Amount of loan used to finance purchase of vessel	$ 39,900
Amount transferred to vessels' cost														$ 29,695
Navios Sphera and Navios Mars \| Navios Partners
Property Plant And Equipment [Line Items]
Disposal date				Aug. 31, 2018
Vessel impairment loss				$ 2,759
Vessel sale price									$ 79,000
Navios Achilles
Property Plant And Equipment [Line Items]
Disposal date				Jul. 31, 2018
Year Built				2001
Vessel capacity in DWT				52,063 dwt
Vessel impairment loss				$ 6,595
Vessel sale price										$ 8,085
Capitalized Cost, Impairment Loss				$ 584
Navios Herakles
Property Plant And Equipment [Line Items]
Disposal date				Mar. 31, 2018
Year Built				2001
Vessel capacity in DWT				52,061 dwt
Vessel impairment loss				$ 6,715
Vessel sale price											$ 7,682
Capitalized Cost, Impairment Loss				$ 481
Navios Equator Prosper
Property Plant And Equipment [Line Items]
Year Built				2000
Date of delivery				Feb. 28, 2018
Vessel capacity in DWT				171,191 dwt
Cash consideration for purchase of vessel				$ 10,255
Navios Ionian
Property Plant And Equipment [Line Items]
Disposal date						Jun. 16, 2017
Year Built						2000
Vessel capacity in DWT						52,067 dwt
Vessel impairment loss						$ 9,098
Vessel sale price													$ 5,280
Capitalized Cost, Impairment Loss						$ 551
Navios Horizon
Property Plant And Equipment [Line Items]
Disposal date						Jul. 13, 2017
Year Built						2001
Vessel capacity in DWT						50,346 dwt
Vessel impairment loss						$ 5,141
Vessel sale price												$ 6,548
Capitalized Cost, Impairment Loss						495
Vessels, Port Terminals and Other Fixed Assets
Property Plant And Equipment [Line Items]
Capitalized interest costs						3,384	$ 1,934
One vessel held and used
Property Plant And Equipment [Line Items]
Impairment loss						$ 32,930

Accrued Expenses and Other Liabilitites (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
ACCRUED EXPENSES AND OTHER LIABILITIES [Abstract]
Payroll		$ 18,889	$ 14,730
Accrued interest		32,555	36,273
Accrued voyage expenses		4,843	2,217
Accrued running costs		23,812	21,394
Provision for estimated losses on vessels under time charter		2,631	3,129
Audit fees and related services		364	266
Accrued taxes		5,376	5,092
Professional fees		2,236	1,707
Other accrued expenses		4,153	6,941
Total accrued expenses	$ 94,515	$ 94,859	$ 91,749

Borrowings (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Secured credit facilities	$ 167,393	$ 219,856
Total borrowings	1,628,585	1,717,768	$ 1,675,415
Less: current portion, net	(32,851)	(33,885)	(29,827)
Less: deferred finance costs, net	(29,254)	(35,280)	(24,320)
Total long-term borrowings	1,566,480	1,648,603	1,621,268
Long Term Loans From Bank	295,754	346,604	274,855
Navios Holdings borrowings
Debt Instrument [Line Items]
Total borrowings		1,174,856	1,240,647
Navios Logistics borrowings
Debt Instrument [Line Items]
Other long-term loans		253	321
2019 Notes
Debt Instrument [Line Items]
Senior Notes		0	291,094
2022 Senior Secured Notes
Debt Instrument [Line Items]
Senior Notes	305,000	305,000	0
2022 Notes
Debt Instrument [Line Items]
Senior Notes	614,339	650,000	650,000
2022 Logistics Senior Notes
Debt Instrument [Line Items]
Senior Notes	375,000	375,000	375,000
Navios Logistics other long-term loans and notes payable
Debt Instrument [Line Items]
Senior Notes		31,109	34,447
Other long-term loans	$ 166,853	167,912
Navios Logistics BBVA Loan Facility
Debt Instrument [Line Items]
Long Term Loans From Bank		23,250	25,000
Navios Logistics Alpha Bank Loan
Debt Instrument [Line Items]
Long Term Loans From Bank		13,300	0
Navios Logistics Term Loan B Facility
Debt Instrument [Line Items]
Long Term Loans From Bank		100,000	0
Total Navios Logistics borrowings \| Navios Logistics borrowings
Debt Instrument [Line Items]
Total borrowings		542,912	434,768
Commerzbank A.G. ($240,000)
Debt Instrument [Line Items]
Secured credit facilities		0	19,857
HSH Nordbank ($15,300)
Debt Instrument [Line Items]
Secured credit facilities		14,535	0
Loan Facility Credit Agricole ($40,000)
Debt Instrument [Line Items]
Secured credit facilities		17,674	18,880
Loan Facility Credit Agricole ($23,000)
Debt Instrument [Line Items]
Secured credit facilities		14,074	14,755
Loan Facility Credit Agricole ($23,000)
Debt Instrument [Line Items]
Secured credit facilities		14,450	15,150
Loan Facility DVB Bank SE ($72,000)
Debt Instrument [Line Items]
Secured credit facilities		50,140	54,540
Loan Facility DVB Bank SE ($41,000)
Debt Instrument [Line Items]
Secured credit facilities		33,816	37,293
Loan Facility Credit Agricole ($22,500)
Debt Instrument [Line Items]
Secured credit facilities		15,188	16,313
Loan Facility DVB Bank SE ($40,000)
Debt Instrument [Line Items]
Secured credit facilities		18,254	28,000
Loan Facility Alpha Bank ($31,000)
Debt Instrument [Line Items]
Secured credit facilities		25,600	27,400
Loan Facility Alpha Bank ($16,125)
Debt Instrument [Line Items]
Secured credit facilities		16,125	16,125
Navios Acquisition Loan
Debt Instrument [Line Items]
Secured credit facilities		$ 0	$ 51,240

Borrowings - Principal Payments (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
BORROWINGS [Abstract]
September 30, 2019	$ 34,840
September 30, 2020	73,216
September 30, 2021	56,817
September 30, 2022	1,426,583
September 30, 2023	33,042
September 30, 2024 and thereafter	4,087
Total	$ 1,628,585	$ 1,717,768	$ 1,675,415
2019		35,988
2020		33,326
2021		71,454
2022		154,825
2023		1,414,638
2024 and thereafter		$ 7,537

Borrowings - Credit Facilities (Details) $ in Thousands	3 Months Ended		5 Months Ended	9 Months Ended		10 Months Ended			12 Months Ended
Borrowings - Credit Facilities (Details) $ in Thousands	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	May 31, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Nov. 03, 2017 USD ($)	Oct. 31, 2016 USD ($)	Oct. 31, 2010 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2010 USD ($)
Debt Instrument [Line Items]
Amount outstanding	$ 167,393			$ 167,393					$ 219,856
Repayment of debt									48,600
Payments related to installments for the current year									25,707
Payments related to installments for the next year									7,286
Total amount of prepayment to affiliate company									(55,132)	$ 50,000	$ 0
Gain/ (Loss) on bond and debt extinguishment	6,464	$ 0		$ 6,464	$ 1,715				$ (981)	29,187	$ 0
Navios Logistics
Debt Instrument [Line Items]
Variable rate basis				LIBOR
Face amount at issuance date	166,853			$ 166,853
Navios Logistics \| Minimum
Debt Instrument [Line Items]
Loan margin percentage				3.15%
Maturity date				Aug. 31, 2020
Navios Logistics \| Maximum
Debt Instrument [Line Items]
Loan margin percentage				4.75%
Maturity date				Nov. 30, 2024
Other long-term loans \| Navios Logistics
Debt Instrument [Line Items]
Line of credit facility issuance date									Oct. 29, 2009
Maximum borrowing capacity									$ 817
Repayment frequency									monthly
Repayment installment									$ 6
Amount outstanding									$ 253	321
Fixed interest rate									6.00%
Repayment terms									The loan facility bears interest at a fixed rate of 600 basis points. The loan is repayable in monthly installments of $6 each and the final repayment must occur prior to August 10, 2021.
Line of Credit
Debt Instrument [Line Items]
Variable rate basis				LIBOR
Line of Credit \| Minimum
Debt Instrument [Line Items]
Loan margin percentage				2.75%
Maturity date				Mar. 31, 2020
Line of Credit \| Maximum
Debt Instrument [Line Items]
Loan margin percentage				3.60%
Maturity date				Nov. 30, 2022
Navios Logistics Notes Payable
Debt Instrument [Line Items]
Maximum borrowing capacity									$ 41,964
Repayment installments									16
Repayment frequency									semi-annual
Interest Rate									six-month LIBOR
Debt finance costs									$ 5,949
Navios Logistics BBVA Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity									$ 25,000
Loan margin percentage									3.25%
Repayment installments									20
Repayment frequency									quarterly
Interest Rate									LIBOR (180 days) plus 325 basis points
One of the secured credit facilities
Debt Instrument [Line Items]
Amount outstanding									$ 17,332
Repayment of debt									15,607
Gain/ (Loss) on bond and debt extinguishment									$ 1,715
Loan Facility Credit Agricole Bank ($40,000) to finance the construction of one newbuilding Capesize vessel
Debt Instrument [Line Items]
Line of credit facility issuance date									Sep. 30, 2010
Maximum borrowing capacity									$ 40,000
Loan margin percentage									2.75%
Interest rate description									LIBOR plus 275 basis points
Balloon payment on the last repayment date									$ 6,810
Amount outstanding									$ 17,674	18,880
Maturity date									Aug. 31, 2021
Loan Facility Credit Agricole Bank ($40,000) to finance the construction of one newbuilding Capesize vessel \| First installment
Debt Instrument [Line Items]
Repayment installments									1
Repayment frequency									quarterly
Repayment installment									$ 2,411
Loan Facility Credit Agricole Bank ($40,000) to finance the construction of one newbuilding Capesize vessel \| From 2nd to 9th installment
Debt Instrument [Line Items]
Repayment installments									7
Repayment frequency									semi-annual
Repayment installment									$ 1,205
Loan Facility Credit Agricole ($23,000) to partially finance the construction of one Panamax vessel
Debt Instrument [Line Items]
Line of credit facility issuance date									Aug. 31, 2011
Maximum borrowing capacity									$ 23,000
Loan margin percentage									2.75%
Interest rate description									LIBOR plus 275 basis points
Balloon payment on the last repayment date									$ 7,264
Amount outstanding									$ 14,074	14,755
Loan Facility Credit Agricole ($23,000) to partially finance the construction of one Panamax vessel \| First installment
Debt Instrument [Line Items]
Repayment installments									1
Repayment frequency									quarterly
Repayment installment									$ 681
Loan Facility Credit Agricole ($23,000) to partially finance the construction of one Panamax vessel \| From 2nd to 10th installment
Debt Instrument [Line Items]
Repayment installments									9
Repayment frequency									semi-annual
Repayment installment									$ 681
Loan Facility Credit Agricole ($23,000) to partially finance the construction of one newbuilding bulk carrier
Debt Instrument [Line Items]
Line of credit facility issuance date									Dec. 31, 2011
Maximum borrowing capacity									$ 23,000
Loan margin percentage									3.25%
Interest rate description									LIBOR plus 325 basis points
Balloon payment on the last repayment date									$ 7,450
Amount outstanding									$ 14,450	15,150
Loan Facility Credit Agricole ($23,000) to partially finance the construction of one newbuilding bulk carrier \| First installment
Debt Instrument [Line Items]
Repayment installments									1
Repayment frequency									quarterly
Repayment installment									$ 700
Loan Facility Credit Agricole ($23,000) to partially finance the construction of one newbuilding bulk carrier \| From 2nd to 10th installment
Debt Instrument [Line Items]
Repayment installments									9
Repayment frequency									semi-annual
Repayment installment									$ 700
Loan Facility Credit Agricole ($22,500) to finance the acquisition of two Panamax Vessels
Debt Instrument [Line Items]
Line of credit facility issuance date									Dec. 20, 2013
Maximum borrowing capacity									$ 22,500
Loan margin percentage									3.00%
Interest rate description									LIBOR plus 300 basis points
Amount outstanding									$ 15,188	16,313
Number Of Loan Tranches									2
Maturity date									Aug. 31, 2021
Debt instrument collateral									1 bulk carrier
Loan Facility Credit Agricole ($22,500) to finance the acquisition of two Panamax Vessels \| Tranche A
Debt Instrument [Line Items]
Balloon payment on the last repayment date									$ 2,812
Loan Facility Credit Agricole ($22,500) to finance the acquisition of two Panamax Vessels \| Tranche B
Debt Instrument [Line Items]
Balloon payment on the last repayment date									$ 2,812
Loan Facility Credit Agricole ($22,500) to finance the acquisition of two Panamax Vessels \| First installment \| Tranche A
Debt Instrument [Line Items]
Repayment installments									1
Repayment frequency									quarterly
Repayment installment									$ 563
Loan Facility Credit Agricole ($22,500) to finance the acquisition of two Panamax Vessels \| First installment \| Tranche B
Debt Instrument [Line Items]
Repayment installments									1
Repayment frequency									quarterly
Repayment installment									$ 1,125
Loan Facility Credit Agricole ($22,500) to finance the acquisition of two Panamax Vessels \| From 2nd to 8th installment \| Tranche A
Debt Instrument [Line Items]
Repayment installments									7
Repayment frequency									semi-annual
Repayment installment									$ 563
Loan Facility Credit Agricole ($22,500) to finance the acquisition of two Panamax Vessels \| From 2nd to 8th installment \| Tranche B
Debt Instrument [Line Items]
Repayment installments									7
Repayment frequency									semi-annual
Repayment installment									$ 563
Commerzbank A.G. to finance acquisition of one Capesize vessel and construction of three Capesize vessels
Debt Instrument [Line Items]
Line of credit facility issuance date									Jun. 30, 2009
Maximum borrowing capacity									$ 240,000
Amount outstanding									$ 0	19,857
Number Of Loan Tranches									4
Amount of each tranche									$ 60,000
Number of the cancellated tranches												2
Commerzbank A.G. to finance acquisition of one Capesize vessel and construction of three Capesize vessels \| Tranche A
Debt Instrument [Line Items]
Repayment of debt								$ 53,600
Commerzbank A.G. to finance acquisition of one Capesize vessel and construction of three Capesize vessels \| Tranche B
Debt Instrument [Line Items]
Repayment of debt								$ 54,500
Commerzbank A.G. to finance acquisition of one Capesize vessel and construction of three Capesize vessels \| Tranche C
Debt Instrument [Line Items]
Amount outstanding							$ 15,319
Repayment of debt							$ 13,802
Gain/ (Loss) on bond and debt extinguishment										1,517
Commerzbank A.G. to finance acquisition of one Capesize vessel and construction of three Capesize vessels \| Tranche D
Debt Instrument [Line Items]
Amount outstanding			$ 17,322
Repayment of debt			$ 15,607
Gain/ (Loss) on bond and debt extinguishment									$ 1,715
HSH Nordbank A.G. ($15,300) to partially refinance the 4th tranche of the Commerzbank facility
Debt Instrument [Line Items]
Line of credit facility issuance date									May 23, 2017
Maximum borrowing capacity									$ 15,300
Loan margin percentage									3.00%
Interest rate description									LIBOR plus 300 basis points
Repayment installments									15
Repayment frequency									quarterly
Repayment installment									$ 383
Balloon payment on the last repayment date									$ 8,798
Loan Facility DVB Bank SE ($72,000)
Debt Instrument [Line Items]
Line of credit facility issuance date									Mar. 23, 2012
Maximum borrowing capacity									$ 42,000
Amount outstanding									$ 50,140	54,540
Number Of Loan Tranches									2
Loan Facility DVB Bank SE ($72,000) \| Tranche A
Debt Instrument [Line Items]
Loan margin percentage									2.85%
Interest rate description									LIBOR plus 285 basis points
Repayment installments									9
Repayment frequency									quarterly
Repayment installment									$ 362
Balloon payment on the last repayment date									14,400
Amount of each tranche									$ 26,000
Loan Facility DVB Bank SE ($72,000) \| Tranche B
Debt Instrument [Line Items]
Loan margin percentage									3.60%
Interest rate description									LIBOR plus 360 basis points
Repayment installments									10
Repayment frequency									quarterly
Repayment installment									$ 269
Balloon payment on the last repayment date									6,354
Amount of each tranche									$ 16,000
Loan Facility DVB Bank SE ($72,000) \| New Tranche June 2014
Debt Instrument [Line Items]
Line of credit facility issuance date									Jun. 27, 2014
Loan margin percentage									2.75%
Interest rate description									LIBOR plus 275 basis points
Repayment installments									10
Repayment frequency									quarterly
Repayment installment									$ 469
Balloon payment on the last repayment date									18,750
Amount of each tranche									$ 30,000
Loan Facility DVB Bank SE ($40,000) to finance the acquisition of four Panamax vessels
Debt Instrument [Line Items]
Line of credit facility issuance date									Sep. 30, 2013
Maximum borrowing capacity									$ 40,000
Loan margin percentage									3.25%
Interest rate description									LIBOR plus 325 basis points
Repayment installments									15
Repayment frequency									quarterly
Repayment installment									$ 730
Balloon payment on the last repayment date									7,302
Amount outstanding									$ 18,254	28,000
Maturity date									Sep. 30, 2021
Debt instrument collateral									1 newbuilding Panamax and 1 newbuilding Capesize vessel
Loan Facility DVB Bank SE ($41,000) to finance the acquisition of one newbuilding Panamax vessel and one newbuilding Capesize vessel
Debt Instrument [Line Items]
Line of credit facility issuance date									Jan. 31, 2016
Maximum borrowing capacity									$ 41,000
Loan margin percentage									2.55%
Interest rate description									LIBOR plus 255 basis points
Amount outstanding									$ 33,816	37,293
Number Of Loan Tranches									2
Amount drawn down										39,900
Loan Facility DVB Bank SE ($41,000) to finance the acquisition of one newbuilding Panamax vessel and one newbuilding Capesize vessel \| Tranche A
Debt Instrument [Line Items]
Balloon payment on the last repayment date									$ 14,760
Loan Facility DVB Bank SE ($41,000) to finance the acquisition of one newbuilding Panamax vessel and one newbuilding Capesize vessel \| Tranche B
Debt Instrument [Line Items]
Balloon payment on the last repayment date									$ 8,764
Loan Facility DVB Bank SE ($41,000) to finance the acquisition of one newbuilding Panamax vessel and one newbuilding Capesize vessel \| First installment \| Tranche A
Debt Instrument [Line Items]
Repayment installments									1
Repayment frequency									quarterly
Repayment installment									$ 492
Loan Facility DVB Bank SE ($41,000) to finance the acquisition of one newbuilding Panamax vessel and one newbuilding Capesize vessel \| First installment \| Tranche B
Debt Instrument [Line Items]
Repayment installments									1
Repayment frequency									quarterly
Repayment installment									$ 377
Loan Facility DVB Bank SE ($41,000) to finance the acquisition of one newbuilding Panamax vessel and one newbuilding Capesize vessel \| From 2nd to 17th installment \| Tranche A
Debt Instrument [Line Items]
Repayment installments									16
Repayment frequency									quarterly
Repayment installment									$ 369
Loan Facility DVB Bank SE ($41,000) to finance the acquisition of one newbuilding Panamax vessel and one newbuilding Capesize vessel \| From 2nd to 17th installment \| Tranche B
Debt Instrument [Line Items]
Repayment installments									16
Repayment frequency									quarterly
Repayment installment									$ 220
Alpha Bank A.E. ($31,000) to finance part of the acquisition of a Capesize vessel
Debt Instrument [Line Items]
Line of credit facility issuance date									Nov. 06, 2014
Maximum borrowing capacity									$ 31,000
Loan margin percentage									3.00%
Interest rate description									LIBOR plus 300 basis points
Repayment installments									20
Repayment frequency									quarterly
Repayment installment									$ 450
Balloon payment on the last repayment date									16,600
Amount outstanding									$ 25,600	27,400
Alpha Bank A.E. ($16,125) to refinance one Capesize vessel
Debt Instrument [Line Items]
Line of credit facility issuance date									Nov. 03, 2016
Maximum borrowing capacity									$ 16,125
Loan margin percentage									3.00%
Interest rate description									LIBOR plus 300 basis points
Balloon payment on the last repayment date									$ 10,725
Amount outstanding									$ 16,125	16,125
Alpha Bank A.E. ($16,125) to refinance one Capesize vessel \| First 4 installments
Debt Instrument [Line Items]
Repayment installments									4
Repayment frequency									quarterly
Repayment installment									$ 250
Alpha Bank A.E. ($16,125) to refinance one Capesize vessel \| From 5th to 21rst installments
Debt Instrument [Line Items]
Repayment installments									16
Repayment frequency									quarterly
Repayment installment									$ 275
Navios Acquisition Loan
Debt Instrument [Line Items]
Line of credit facility issuance date				Sep. 19, 2016					Sep. 19, 2016
Maximum borrowing capacity	$ 70,000			$ 70,000					$ 70,000
Amount outstanding									$ 0	51,240
Repayment of debt				60,716
Payments related to installments for the current year				28,947
Payments related to installments for the next year				$ 31,769
Total amount of prepayment to affiliate company						$ (55,132)				$ 50,000
Prepayment amount of loan to affiliate company, net						50,000
Accrued interest						$ 5,132

Borrowings - Additional Information (Details)	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Annual weighted average interest rate		7.11%		6.87%	6.98%
Three months ended
Debt Instrument [Line Items]
Annual weighted average interest rate	7.82%		7.19%
Nine months ended
Debt Instrument [Line Items]
Annual weighted average interest rate	7.75%		6.96%

Borrowings - Repayment Terms and Covenants (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Navios Holdings borrowings
Debt Instrument [Line Items]
Repayment terms	The credit facilities contain a number of restrictive covenants that limit Navios Holdings and/or certain of its subsidiaries from, among other things: incurring or guaranteeing indebtedness; entering into affiliate transactions; charging, pledging or encumbering the vessels securing such facilities; changing the flag, class, management or ownership of certain Navios Holdings’ vessels; changing the commercial and technical management of certain Navios Holdings’ vessels; selling or changing the ownership of certain Navios Holdings’ vessels; and subordinating the obligations under the credit facilities to any general and administrative costs relating to the vessels. The credit facilities also require the vessels to comply with the ISM Code and ISPS Code and to maintain valid safety management certificates and documents of compliance at all times. Additionally, the credit facilities require compliance with the covenants contained in the indentures governing the 2022 Senior Secured Notes (as defined below) and the 2022 Notes (as defined below). Among other events, it will be an event of default under the credit facilities if the financial covenants are not complied with or if Angeliki Frangou and her affiliates, together, own less than 20% of the outstanding share capital of Navios Holdings.	The credit facilities contain a number of restrictive covenants that limit Navios Holdings and/or certain of its subsidiaries from, among other things: incurring or guaranteeing indebtedness; entering into affiliate transactions; charging, pledging or encumbering the vessels securing such facilities; changing the flag, class, management or ownership of certain Navios Holdings’ vessels; changing the commercial and technical management of certain Navios Holdings’ vessels; selling or changing the ownership of certain Navios Holdings’ vessels; and subordinating the obligations under the credit facilities to any general and administrative costs relating to the vessels. The credit facilities also require the vessels to comply with the ISM Code and ISPS Code and to maintain valid safety management certificates and documents of compliance at all times. Additionally, the credit facilities require compliance with the covenants contained in the indentures governing the 2022 Senior Secured Notes and the 2022 Notes. Among other events, it will be an event of default under the credit facilities if the financial covenants are not complied with or if Angeliki Frangou and her affiliates, together, own less than 20% of the outstanding share capital of Navios Holdings.
2022 Notes \| Navios Holdings borrowings
Debt Instrument [Line Items]
Repayment terms	The guarantees of the Company’s subsidiaries that own mortgaged vessels are senior secured guarantees and the guarantees of the Company’s subsidiaries that do not own mortgaged vessels are senior unsecured guarantees. In addition, the 2022 Co-Issuers have the option to redeem the 2022 Notes in whole or in part, at any time on or after January 15, 2017, at a fixed price of 105.531%, which price declines ratably until it reaches par in 2020.	The guarantees of the Company's subsidiaries that own mortgaged vessels are senior secured guarantees and the guarantees of the Company's subsidiaries that do not own mortgaged vessels are senior unsecured guarantees. In addition, the 2022 Co-Issuers have the option to redeem the 2022 Notes in whole or in part, at any time on or after January 15, 2017, at a fixed price of 105.531%, which price declines ratably until it reaches par in 2020.
Debt Instrument Covenant Description	Upon occurrence of certain change of control events, the holders of the 2022 Notes may require the 2022 Co-Issuers to repurchase some or all of the 2022 Notes at 101% of their face amount. The 2022 Notes contain covenants, which among other things, limit the incurrence of additional indebtedness, issuance of certain preferred stock, the payment of dividends, redemption or repurchase of capital stock or making restricted payments and investments, creation of certain liens, transfer or sale of assets, entering into certain transactions with affiliates, merging or consolidating or selling all or substantially all of the 2022 Co-Issuers’ properties and assets and creation or designation of restricted subsidiaries. The indenture governing the 2022 Notes includes customary events of default. The 2022 Co-Issuers were in compliance with the covenants as of September 30, 2018.	Furthermore, upon occurrence of certain change of control events, the holders of the 2022 Notes may require the 2022 Co-Issuers to repurchase some or all of the 2022 Notes at 101% of their face amount. The 2022 Notes contain covenants, which among other things, limit the incurrence of additional indebtedness, issuance of certain preferred stock, the payment of dividends, redemption or repurchase of capital stock or making restricted payments and investments, creation of certain liens, transfer or sale of assets, entering into certain transactions with affiliates, merging or consolidating or selling all or substantially all of the 2022 Co-Issuers' properties and assets and creation or designation of restricted subsidiaries. The 2022 Co-Issuers were in compliance with the covenants as of December 31, 2017.
Other long-term loans \| Navios Logistics
Debt Instrument [Line Items]
Repayment terms		The loan facility bears interest at a fixed rate of 600 basis points. The loan is repayable in monthly installments of $6 each and the final repayment must occur prior to August 10, 2021.
2022 Logistics Senior Notes \| Navios Logistics
Debt Instrument [Line Items]
Repayment terms	The Logistics Co-Issuers have the option to redeem the 2022 Logistics Senior Notes in whole or in part, at their option, at any time on or after May 1, 2017, at a fixed price of 105.438%, which price declines ratably until it reaches par in 2020. Upon the occurrence of certain change of control events, the holders of the 2022 Logistics Senior Notes will have the right to require the Logistics Co-Issuers to repurchase some or all of the 2022 Logistics Senior Notes at 101% of their face amount, plus accrued and unpaid interest to the repurchase date.	The Logistics Co-Issuers have the option to redeem the 2022 Logistics Senior Notes in whole or in part, at their option, at any time on or after May 1, 2017, at a fixed price of 105.438%, which price declines ratably until it reaches par in 2020. In addition, upon the occurrence of certain change of control events, the holders of the 2022 Logistics Senior Notes will have the right to require the Logistics Co-Issuers to repurchase some or all of the 2022 Logistics Senior Notes at 101% of their face amount, plus accrued and unpaid interest to the repurchase date.
Debt Instrument Covenant Description	The indenture governing the 2022 Logistics Senior Notes contains covenants which, among other things, limit the incurrence of additional indebtedness, issuance of certain preferred stock, the payment of dividends, redemption or repurchase of capital stock or making restricted payments and investments, creation of certain liens, transfer or sale of assets, entering into transactions with affiliates, merging or consolidating or selling all or substantially all of Navios Logistics’ properties and assets and creation or designation of restricted subsidiaries.	The indenture governing the 2022 Logistics Senior Notes contains covenants which, among other things, limit the incurrence of additional indebtedness, issuance of certain preferred stock, the payment of dividends in excess of 6% per annum of the net proceeds received by or contributed to Navios Logistics in or from any public offering, redemption or repurchase of capital stock or making restricted payments and investments, creation of certain liens, transfer or sale of assets, entering into transactions with affiliates, merging or consolidating or selling all or substantially all of Navios Logistics’ properties and assets and creation or designation of restricted subsidiaries.
Secured debt
Debt Instrument [Line Items]
Minimum liquidity	$ 30,000	$ 30,000
Secured debt \| Minimum
Debt Instrument [Line Items]
Value to loan ratio	1.15	1.1
Net total debt to assets	0.75	0.75
Secured debt \| Minimum \| Covenants waived up to one quarter
Debt Instrument [Line Items]
Net total debt to assets	0.85
Secured debt \| Maximum
Debt Instrument [Line Items]
Value to loan ratio	1.35	1.35
Net total debt to assets	0.8	0.8
Secured debt \| Maximum \| Covenants waived up to four quarters
Debt Instrument [Line Items]
Net total debt to assets		0.9
Secured debt \| Maximum \| Covenants waived up to one quarter
Debt Instrument [Line Items]
Net total debt to assets	0.9
Loan Facility Credit Agricole ($40,000) \| Navios Holdings borrowings
Debt Instrument [Line Items]
Repayment terms		As of December 31, 2017, the outstanding amount under the loan facility was repayable in one quarterly installment of $2,411, followed by seven semi-annual equal installments of $1,205 with a final balloon payment of $6,810 on the last payment date.
Loan Facility Credit Agricole ($23,000) \| Navios Holdings borrowings
Debt Instrument [Line Items]
Repayment terms		As of December 31, 2017, the facility is repayable in one quarterly installment of $681, followed by nine semi-annual equal installments of $681, with a final balloon payment of $7,264 on the last payment date.
Loan Facility Credit Agricole ($23,000) \| Navios Holdings borrowings
Debt Instrument [Line Items]
Repayment terms		As of December 31, 2017, the outstanding amount under the loan facility was repayable in one quarterly installment of $700 after the drawdown date, followed by nine semi-annual equal installments of $700, with a final balloon payment of $7,450 on the last payment date.
Loan Facility Credit Agricole ($22,500) \| Navios Holdings borrowings
Debt Instrument [Line Items]
Repayment terms		The first tranche is repayable in one quarterly installment of $563, followed by seven equal semi-annual installments of $563, with a final balloon payment of $2,812 on the last repayment date. The second tranche is repayable in one quarterly installment of $1,125, followed by seven equal semi-annual installments of $563, with a final balloon payment of $2,812 on the last repayment date.
Loan Facility DVB Bank SE ($72,000) \| Navios Holdings borrowings
Debt Instrument [Line Items]
Repayment terms		As of December 31, 2017, the first tranche is repayable in nine quarterly installments of $362, with a final balloon payment of $14,400 on the last repayment date, the second tranche is repayable in ten quarterly installments of $269, with a final balloon payment of $6,354 on the last repayment date and the third tranche is repayable in ten quarterly installments of $469, with a final balloon payment of $18,750 on the last repayment date.
Loan Facility DVB Bank SE ($40,000) \| Navios Holdings borrowings
Debt Instrument [Line Items]
Repayment terms		As of December 31, 2017, the facility is repayable in 15 quarterly installments of $730, with a final balloon payment of $7,302 payable on the last repayment date.
Loan Facility Alpha Bank ($31,000) \| Navios Holdings borrowings
Debt Instrument [Line Items]
Repayment terms		As of December 31, 2017, the facility is repayable in 20 quarterly installments of $450, with a final balloon payment of $16,600 on the last repayment date.

Fair Value of Financial Instruments - Fair Value (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents - Book Value	$ 132,925	$ 127,632	$ 114,198	$ 135,992	$ 163,412	$ 247,556
Cash and cash equivalents - Fair Value	132,925	127,632		135,992
Restricted cash - Book Value	10,056	6,558	$ 5,040	5,386	$ 13,480
Restricted cash - Fair Value	10,056	6,558		5,386
Loan receivable from affiliate companies - Book Value	34,635	30,112		23,008
Loan receivable from affiliate companies - Fair Value	34,635	30,112		23,008
Investments in available-for-sale securities - Book Value	227	238		0
Investments in available-for-sale securities - Fair Value	227	238		0
Senior and ship mortgage notes, net - Book Value	(1,270,726)	(1,301,999)		(1,296,537)
Senior and ship mortgage notes, net - Fair Value	(1,112,673)	(1,181,838)		(974,170)
Long-term debt, including current portion - Book Value	(328,605)	(380,489)		(304,682)
Long-term debt, including current portion - Fair Value	(335,301)	(389,332)		(308,080)
Long term payable to affiliate companies - Book Value	(86,005)	(76,872)		(6,399)
Long term payable to affiliate companies - Fair Value	$ (86,005)	(76,872)		(6,399)
Long-term receivable from affiliate companies - Book Value				11,105
Long-term receivable from affiliate companies - Fair Value		0		11,105
Capital lease obligations, including current portion - Book Value		0		(17,617)
Capital lease obligations, including current portion - Fair Value		0		(17,617)
Loan payable to affiliate company - Book Value		0		(49,876)
Loan payable to affiliate company - Fair Value		$ 0		$ (51,240)

Fair Value of Financial Instruments - Recurring Measurements (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Investments in available-for-sale securities	$ 227	$ 238	$ 0
Fair Value, Measurements, Recurring
Assets
Investments in available-for-sale securities	227	238
Total	227	238
Quoted Prices in Active Markets for Identical Assets (Level I) \| Fair Value, Measurements, Recurring
Assets
Investments in available-for-sale securities	227	238
Total	$ 227	$ 238

Fair Value of Financial Instruments - Assets measured at Fair Value on a Non-Recurring Basis (Table) (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Vessels, port terminals and other fixed assets, net	$ 16,500
Investments in affiliates	16,500	$ 148,095
Quoted Prices in Active Markets for Identical Assets (Level I)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments in affiliates		$ 148,095
Significant Other Observable Inputs (Level II)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Vessels, port terminals and other fixed assets, net	16,500
Investments in affiliates	$ 16,500

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment loss	$ (34)	$ 50,565	$ 0	$ 0
Loss on investments in Navios Partners and Navios Aqcuisition			$ 228,026
One vessel
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment loss		$ 32,930

Employee Benefit Plans (Table) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Shares
Options
Outstanding, shares	7,904,576	8,796,246	6,644,766	5,804,594
Vested, shares	1,210,824	730,592	1,643,665
Exercisable, shares	1,210,824	730,592	1,500,476
Forfeited or expired, shares	(891,670)	(348,520)	(159,828)
Granted, shares		2,500,000	1,000,000
Restricted stock and restricted stock units
Non Vested, shares	7,017,314	4,502,534	3,720,959	1,997,344
Granted, shares	4,353,975	2,540,000	2,540,000
Vested, shares	(1,839,195)	(1,755,017)	(812,847)
Forfeited or expired, shares		(3,408)	(3,538)
Weighted average exercise price
Options
Outstanding	$ 2.98	$ 3.2	$ 4.09	$ 4.57
Granted		$ 1.2	$ 1.2
Weighted average remaining term
Options
Weighted average remaining term	3 years 9 months 18 days	4 years 4 months 28 days	4 years 2 months 23 days	4 years 7 months 20 days
Restricted stock and restricted stock units
Weighted average remaining term	3 years 2 months 16 days	2 years 6 months 19 days	2 years 5 months 13 days	2 years
Aggregate fair value
Options
Outstanding, value	$ 7,539	$ 9,804	$ 8,769	$ 8,410
Forfeited or expired, value			(193)
Granted, value			552
Restricted stock and restricted stock units
Non vested, value	3,512	6,100	8,186	$ 10,899
Granted, value	42	3,048	3,048
Vested, value	$ (2,630)	(5,122)	(5,746)
Forfeited or expired, value		$ (12)	$ (15)

Commitments - Navios Holdings Future Minimum Commitments for Chartered-In Vessels, Barges and Pushboats (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Charter-in Vessels, barges and pushboats in operation
Operating Leased Assets [Line Items]
September 30, 2019	$ 116,882
September 30, 2020	104,591
September 30, 2021	76,120
September 30, 2022	48,112
September 30, 2023	37,640
September 30, 2024 and thereafter	50,350
Total	433,695	$ 482,266
Charter-in vessels to be delivered
Operating Leased Assets [Line Items]
September 30, 2019	6,674
September 30, 2020	15,226
September 30, 2021	17,080
September 30, 2022	16,883
September 30, 2023	16,463
September 30, 2024 and thereafter	49,683
Total	$ 122,009	$ 89,273

Commitments and Contingencies (Details) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended	9 Months Ended		12 Months Ended
Commitments and Contingencies (Details) $ in Thousands	Feb. 10, 2017 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2016 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Letters of guarantee and letters of credit				$ 600		$ 590	$ 590
Cash consideration for purchase of vessel				10,647	$ 0	0	60,115	$ 0
Other long term assets				42,479		37,801	2,647
Other income						6,140	18,175	4,840
Restricted cash				10,056	$ 5,040	6,558	5,386	$ 13,480
Scenario, Previously Reported [Member]
Other long term assets						$ 4,856
Navios Logistics
Collateralized cash amount released		$ 2,900					2,900
Revolver \| Navios Acquisition
Maximum borrowing capacity							50,000
Litigation settlement expense			$ 775
Settlement agreement date						Jun. 09, 2016
Lawsuit filing date						Apr. 01, 2016
Letter of Credit \| Navios Logistics
Restricted cash							$ 2,900
Vitol S.A. \| Navios Logistics
Guarantee and indemnity letter				$ 12,000		$ 12,000
Guarantees				Navios Logistics issued a guarantee and indemnity letter that guarantees the performance by Petrolera San Antonio S.A. (a consolidated subsidiary) of all its obligations to Vitol S.A. up to $12,000. This guarantee expires on March 1, 2019.		Navios Logistics has issued a guarantee and indemnity letter that guarantees the performance by Petrolera San Antonio S.A. (a consolidated subsidiary) of all its obligations to Vitol S.A. up to $12,000. This guarantee expires on March 1, 2019.
Vale \| Navios Logistics
Litigation Settlement, Amount Awarded from Other Party	$ 21,500
Other income		$ 1,157				$ 1,157
Three pushboats \| Navios Logistics
Contractual obligation next twelve months						$ 580
Bulk carrier vessel
Vessel capacity in DWT				82,000 dwt		82,000 dwt
Date of expected delivery				Q1 2020		Q4 2019
Cash consideration for purchase of vessel						$ 2,705
Other long term assets				$ 2,896		2,724
Contractual Obligation				$ 5,410		$ 5,410
Construction of river and estuary tanker
Lease Term						5 years
Construction of river and estuary tanker \| Navios Logistics
Contractual obligation next twelve months						$ 9,024
Newbuilding bulk carriers
Lease Term				10 years
Number of vessels				2
Cash consideration for purchase of vessel				$ 5,570
Other long term assets				5,989
Contractual obligation next twelve months				$ 11,140
First newbuilding bulk carrier
Vessel capacity in DWT				82,000 dwt
Date of expected delivery				Q3 2019
Second newbuilding bulk carrier
Vessel capacity in DWT				82,000 dwt
Date of expected delivery				Q4 2019
Bulk carrier vessel
Lease Term				10 years
Number of vessels				1
Vessel capacity in DWT				81,000 dwt
Date of expected delivery				Q4 2019
Cash consideration for purchase of vessel				$ 2,795
Other long term assets				2,945
Contractual obligation next twelve months				$ 5,590
Covers for Dry Barges
Contractual Obligation						1,115
Covers for Dry Barges \| Navios Logistics
Contractual Obligation						1,115
Contractual obligation next twelve months						$ 486

Leases - Navios Holdings Future Minimum Commitments for Chartered-In Vessels, Barges, Pushboats and Office Space (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Charter-in vessels in operation
Operating Leased Assets [Line Items]
2018		$ 119,023
2019		96,048
2020		82,638
2021		63,040
2022		43,689
2023 and thereafter		77,828
Total	$ 433,695	482,266
Charter-in vessels to be delivered
Operating Leased Assets [Line Items]
2018		8,725
2019		19,316
2020		20,945
2021		10,807
2022		10,109
2023 and thereafter		19,371
Total	$ 122,009	89,273
Office space
Operating Leased Assets [Line Items]
2018		1,992
2019		1,314
2020		509
2021		184
2022		0
2023 and thereafter		0
Total		$ 3,999

Leases - Navios Holdings Future Revenue for Chartered-Out Vessels, Barges, Pushboats and for Logistics Business (Table) (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Dry bulk vessels
Property Subject To Or Available For Operating Lease [Line Items]
2018	$ 35,420
2019	2,458
2020	0
2021	0
2022	0
Total minimum revenue, net of commissions	37,878
Logistics business
Property Subject To Or Available For Operating Lease [Line Items]
2018	138,384
2019	104,721
2020	77,209
2021	62,290
2022	55,450
2023 and thereafter	699,388
Total minimum revenue, net of commissions	$ 1,137,442

Leases (Details) - USD ($) $ in Thousands	12 Months Ended
Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Logistics business
Property Subject To Or Available For Operating Lease [Line Items]
Charter hire expense	$ 1,564	$ 1,521	$ 1,307
Future minimum revenue	1,137,442
Chartered-in vessels
Property Subject To Or Available For Operating Lease [Line Items]
Rent expense for office space	2,648	2,748	2,508
Charter hire expense	122,668	$ 84,114	$ 134,364
Construction of river and estuary tanker
Property Subject To Or Available For Operating Lease [Line Items]
Future minimum revenue	$ 41,380
Lease term	5 years

Transactions with Related Parties - Vessels Charter Hire and Management Fees (Details) - USD ($)	1 Months Ended	2 Months Ended	3 Months Ended		5 Months Ended		9 Months Ended			11 Months Ended			12 Months Ended
	Jan. 31, 2016	Dec. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Jun. 07, 2017	Jun. 05, 2015	Sep. 30, 2018	Oct. 31, 2017	Sep. 30, 2017	Nov. 30, 2016	Nov. 18, 2014	Dec. 13, 2013	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Voyage expenses			$ 0	$ 0			$ 0		$ 651,000				$ 651,000	$ 1,711,000	$ 39,727,000
Minimum \| Navios Partners for the Navios Gemini, Navios Hyperion, Navios Soleil, Navios Harmony, Navios Orbiter, Navios Fantastiks, Navios Alegria, Navios Pollux and Navios Sun
Lease term							9 months						9 months
Maximum \| Navios Partners for the Navios Gemini, Navios Hyperion, Navios Soleil, Navios Harmony, Navios Orbiter, Navios Fantastiks, Navios Alegria, Navios Pollux and Navios Sun
Lease term							12 months						12 months
Charter hire agreement \| Navios Fantastiks
Charter hire daily rate							$ 12,500						$ 12,500
Charter hire agreement \| Navios Gemini
Charter hire daily rate							7,600						7,600
Charter hire agreement \| Navios Pollux
Charter hire daily rate							11,400						11,400
Charter hire agreement \| Navios Sun, Navios Orbiter, Navios Soleil, Navios Alegria, Navios Harmony and Navios Hyperion
Charter hire daily rate							$ 12,000						$ 12,000
Charter hire agreement \| Navios Partners for the Navios Gemini, Navios Hyperion, Navios Soleil, Navios Harmony, Navios Orbiter, Navios Fantastiks, Navios Alegria, Navios Pollux and Navios Sun
Profit sharing, Percentage allocation based on earnings							50.00%						50.00%
Charter hire agreement \| Navios Fulvia
Date of agreement							Nov. 30, 2016						Nov. 30, 2016
Charter hire daily rate							$ 11,500						$ 11,500
Duration of agreements										3 months
Extended charter hire agreement \| Navios Apollon
Date of agreement													Apr. 30, 2015
Lease term													one year
Charter hire daily rate													$ 12,500
Profit sharing, Percentage allocation based on earnings													50.00%
Extended charter hire agreement \| Navios Libra
Date of agreement													Apr. 30, 2015
Lease term													one year
Charter hire daily rate													$ 12,000
Profit sharing, Percentage allocation based on earnings													50.00%
Extended charter hire agreement \| Navios Felicity
Date of agreement													Apr. 30, 2015
Lease term													one year
Charter hire daily rate													$ 12,000
Profit sharing, Percentage allocation based on earnings													50.00%
Extended charter hire agreement \| Navios Hope
Date of agreement													Apr. 30, 2015
Lease term													one year
Charter hire daily rate													$ 10,000
Profit sharing, Percentage allocation based on earnings													50.00%
Navios Partners
Termination date of the administrative services agreement							December 31, 2022						December 31, 2022
Management fees			17,220	16,270			$ 51,292		44,936				$ 62,157	59,209	56,504
Terms of reimbursement of fees and expenses under the management agreement													Effective August 31, 2016, Navios Partners could, upon request to Navios Holdings, partially or fully defer the reimbursement of dry docking and other extraordinary fees and expenses under the management agreement to a later date, but not later than January 5, 2018, and if reimbursed on a later date, such amounts would bear interest at a rate of 1% per annum over LIBOR.
Navios Partners \| Ultra-Handymax vessel
Daily management fee	$ 4,000	$ 4,200					4,200	$ 4,100
Navios Partners \| Panamax vessel
Daily management fee	4,100	4,300					4,300	4,200
Navios Partners \| Capesize vessel
Daily management fee	5,100	5,250					5,250	5,250
Navios Partners \| Container vessel of 6,800 TEU
Daily management fee	6,500	6,700					6,700	6,700
Navios Partners \| Container vessel more than 8,000 TEU
Daily management fee	7,200	7,400					7,400	7,400
Navios Partners \| Container vessel more than 13,000 TEU
Daily management fee	$ 8,500	$ 8,750					$ 8,750	$ 8,750
Navios Acquisition
Termination date of the administrative services agreement							May 2020						May 2020
Management fees			23,340,000	23,938,000			$ 69,652,000		71,035,000				$ 94,973,000	97,866,000	95,336,000
Navios Acquisition \| Extended charter hire agreement \| LR1 product tanker vessel
Daily management fee							$ 7,000						$ 7,000
Duration of agreements							2 years						2 years
Navios Acquisition \| Extended management agreement \| MR2 product tanker and chemical tanker vessel
Daily management fee							$ 6,000						$ 6,000
Duration of agreements							2 years						2 years
Navios Acquisition \| Extended management agreement \| VLCC vessel
Daily management fee							$ 9,500						$ 9,500
Duration of agreements							2 years						2 years
Navios Acquisition \| Amendement of management agreement
Termination date of the administrative services agreement							May 31, 2018						May 31, 2018
Navios Acquisition \| Amendement of management agreement \| MR2 product tanker and chemical tanker vessel
Daily management fee							$ 6,350						$ 6,350
Navios Acquisition \| Amendement of management agreement \| LR1 product tanker vessel
Daily management fee							7,150						7,150
Navios Acquisition \| Amendement of management agreement \| VLCC vessel
Daily management fee							9,500						9,500
Navios Acquisition \| Further amendement of management agreement \| MR2 product tanker and chemical tanker vessel
Daily management fee							6,500
Navios Acquisition \| Further amendement of management agreement \| LR1 product tanker vessel
Daily management fee							7,150
Navios Acquisition \| Further amendement of management agreement \| VLCC vessel
Daily management fee							9,500
Navios Europe I
Management fees			5,942,000	5,227,000			16,318,000		15,820,000				21,472,000	20,855,000	20,383,000
Navios Europe I \| Management agreement
Duration of agreements												6 years
Navios Midstream
Management fees			5,244,000	5,244,000			$ 15,495,000		15,561,000				$ 20,805,000	20,862,000	17,613,000
Navios Midstream \| Management agreement
Duration of agreements											5 years
Navios Midstream \| Management agreement \| VLCC vessel
Termination date of the administrative services agreement							Dec. 31, 2018						Dec. 31, 2018
Daily management fee							$ 9,500						$ 9,500
Navios Europe II
Management fees			5,556,000	5,058,000			16,357,000		16,244,000				22,055,000	$ 23,527,000	$ 9,581,000
Navios Europe II \| Management agreement
Duration of agreements						6 years
Navios Containers \| Container vessel of 4,250 TEU
Daily management fee													6,100
Navios Containers \| Container vessel of 3,450 TEU
Daily management fee													6,100
Navios Containers \| Container vessel of 5,500 TEU
Daily management fee													6,100
Navios Containers \| Container vessel more than 5,500 TEU
Daily management fee							6,100
Navios Containers \| Container vessel more than 5,500 TEU and up to 8,000 TEU
Daily management fee							6,700
Navios Containers \| Container vessel more than 8,000 TEU and up to 10,000 TEU
Daily management fee							7,400
Navios Containers \| Management agreement
Management fees			$ 14,490,000	$ 6,576,000			$ 38,578,000		$ 7,491,000				$ 16,702,000
Duration of agreements					5 years
Navios Containers \| Automatic extension of management agreement
Duration of agreements							5 years						5 years

Other Expense, Net (Details) - USD ($) $ in Thousands	2 Months Ended	3 Months Ended	9 Months Ended		12 Months Ended
Other Expense, Net (Details) - USD ($) $ in Thousands	Feb. 28, 2017	Mar. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Formosa and San Lorenzo
Schedule Of Equity Method Investments [Line Items]
Vessel sale price	$ 1,109
Default credit insurance policy
Schedule Of Equity Method Investments [Line Items]
Cash exchanged due to early redelivery of vessel		$ 13,000
Claims payable to the charterer extinguishmed		1,871
Gain on contract termination		$ 14,871
Navios Logistics \| Other income
Schedule Of Equity Method Investments [Line Items]
Other (expense)/income - taxes other than income taxes			$ 5,117	$ 6,885
Navios Logistics \| Other expense
Schedule Of Equity Method Investments [Line Items]
Other (expense)/income - taxes other than income taxes					$ 9,018	$ 9,740	$ 11,976
Navios Logistics \| Formosa and San Lorenzo
Schedule Of Equity Method Investments [Line Items]
Vessel sale price	1,109
Gain on sale of assets	$ 1,030

Segment Information (Table) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenue	$ 141,453	$ 120,555	$ 390,386	$ 334,519	$ 463,049	$ 419,782	$ 480,820
Administrative fee revenue from affiliates	7,357	6,284	21,488	16,942	23,667	21,799	16,177
Interest income					6,831	4,947	2,370
Interest expense and finance cost, net	(32,734)	(28,825)	(97,797)	(83,812)	(121,611)	(113,639)	(113,151)
Depreciation and amortization	(24,644)	(26,179)	(75,247)	(77,893)	(104,112)	(113,825)	(120,310)
Equity in net (losses)/earnings of affiliated companies	(4,231)	901	(13,720)	2,208	4,399	(202,779)	61,484
Net (loss)/income attributable to Navios Holdings common stockholders	(1,816)	(28,332)	(67,965)	(114,309)	(165,910)	(303,823)	(134,112)
Total assets	2,488,857	2,660,607	2,488,857	2,660,607	2,629,981	2,752,895	2,958,813
Goodwill	160,336	160,336	160,336	160,336	160,336	160,336	160,336
Capital expenditures	(11,384)	(7,395)	(29,876)	(36,565)	(46,868)	(151,593)	(34,921)
Investments in affiliates	166,888	185,548	166,888	185,548	183,160	160,071	381,746
Cash and cash equivalents	132,925	114,198	132,925	114,198	127,632	135,992	163,412	$ 247,556
Restricted cash	10,056	5,040	10,056	5,040	6,558	5,386	13,480
Long-term debt (including current and noncurrent portion)	1,599,331	1,643,215	1,599,331	1,643,215	1,682,488	1,651,095	1,581,308
Dry bulk Vessel Operations
Segment Reporting Information [Line Items]
Revenue	85,533	60,976	222,135	171,758	250,433	199,446	229,772
Administrative fee revenue from affiliates	7,357	6,284	21,488	16,942	23,667	21,799	16,177
Interest income					6,593	4,132	1,801
Interest expense and finance cost, net	(22,778)	(21,379)	(68,599)	(64,290)	(93,264)	(89,399)	(86,069)
Depreciation and amortization	(17,389)	(19,023)	(53,612)	(58,269)	(77,245)	(87,197)	(92,341)
Equity in net (losses)/earnings of affiliated companies	(4,231)	901	(13,720)	2,208	4,399	(202,779)	61,484
Net (loss)/income attributable to Navios Holdings common stockholders	(6,111)	(29,509)	(74,141)	(116,394)	(167,892)	(310,306)	(148,306)
Total assets	1,806,177	1,996,951	1,806,177	1,996,951	1,947,777	2,083,526	2,359,299
Goodwill	56,240	56,240	56,240	56,240	56,240	56,240	56,240
Capital expenditures	(1,301)	(161)	(13,747)	(261)	(347)	(60,420)	(7,882)
Investments in affiliates	166,888	185,548	166,888	185,548	183,160	160,071	381,746
Cash and cash equivalents	50,378	46,155	50,378	46,155	47,744	70,810	81,905
Restricted cash	10,056	5,040	10,056	5,040	6,558	2,486	13,480
Long-term debt (including current and noncurrent portion)	1,066,080	1,204,234	1,066,080	1,204,234	1,149,742	1,223,146	1,213,740
Logistics Business
Segment Reporting Information [Line Items]
Revenue	55,920	59,579	168,251	162,761	212,616	220,336	251,048
Administrative fee revenue from affiliates	0	0	0	0	0	0	0
Interest income					238	815	569
Interest expense and finance cost, net	(9,956)	(7,446)	(29,198)	(19,522)	(28,347)	(24,240)	(27,082)
Depreciation and amortization	(7,255)	(7,156)	(21,635)	(19,624)	(26,867)	(26,628)	(27,969)
Equity in net (losses)/earnings of affiliated companies	0	0	0	0	0	0	0
Net (loss)/income attributable to Navios Holdings common stockholders	4,295	1,177	6,176	2,085	1,982	6,483	14,194
Total assets	682,680	663,656	682,680	663,656	682,204	669,369	599,514
Goodwill	104,096	104,096	104,096	104,096	104,096	104,096	104,096
Capital expenditures	(10,083)	(7,234)	(16,129)	(36,304)	(46,521)	(91,173)	(27,039)
Investments in affiliates	0	0	0	0	0	0	0
Cash and cash equivalents	82,547	68,043	82,547	68,043	79,888	65,182	81,507
Restricted cash	0	0	0	0	0	2,900	0
Long-term debt (including current and noncurrent portion)	$ 533,251	$ 438,981	$ 533,251	$ 438,981	$ 532,746	$ 427,949	$ 367,568

Loss Per Common Share (Table) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator:
Net loss attributable to Navios Holdings common stockholders	$ (1,816)	$ (28,332)	$ (67,965)	$ (114,309)	$ (165,910)	$ (303,823)	$ (134,112)
Declared and undeclared dividend on preferred stock and on unvested restricted shares	(2,566)	(2,555)	(7,679)	(7,859)	(10,421)	(15,909)	(16,202)
Tender Offer - Redemption of preferred stock Series G and H including $972 and $5,063 of undeclared preferred dividend cancelled for the year ended December 31, 2017 and December 31, 2016, respectively	0	615	0	1,119	1,033	46,627	0
Loss attributable to Navios Holdings common stockholders, basic and diluted	$ (4,382)	$ (30,272)	$ (75,644)	$ (121,049)	$ (175,298)	$ (273,105)	$ (150,314)
Denominator:
Denominator for basic and diluted net loss per share attributable to Navios Holdings common stockholders — weighted average shares	119,423,135	117,535,234	119,423,025	116,260,640	166,673,459	107,366,783	105,896,235
Basic and diluted net losses per share attributable to Navios Holdings common stockholders	$ (0.04)	$ (0.26)	$ (0.63)	$ (1.04)	$ (1.5)	$ (2.54)	$ (1.42)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Loss Per Common Share (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
Loss Per Common Share (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Undeclared preferred dividends			$ 27,372
Common shares
Shares with anti-dilutive effect, not included in calculation of earnings per share	7,012,813	5,035,167	6,761,637	5,307,928	5,033,156	3,411,270	1,698,569
Convertible Preferred Stock
Shares with anti-dilutive effect, not included in calculation of earnings per share	3,499,000	3,499,000	3,499,000	4,926,692	4,566,836	5,935,000	6,522,556

Investments in affiliates and investments in available-for-sale securities (Table) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Navios Partners
Balance sheet
Cash and cash equivalents, including restricted cash	$ 58,322		$ 58,322		$ 29,933	$ 25,088
Current assets	89,350		89,350		60,306	56,349
Non-current assets	1,239,273		1,239,273		1,244,996	1,212,231
Current liabilities	54,075		54,075		54,247	98,950
Long- term debt including current portion, net	511,669		511,669		493,463	523,776
Non-current liabilities	491,262		491,262		483,345	489,421
Income Statement
Revenue	62,571	$ 59,954	173,819	$ 152,383	211,652	190,524	$ 223,676
Net (loss)/ income before non-cash change in fair value of Junior Loan I and Junior Loan II					(15,090)	(52,549)	41,805
Net income/ (loss)	10,457	9,173	(13,598)	7,965	(15,090)	(52,549)	41,805
Navios Acquisition
Balance sheet
Cash and cash equivalents, including restricted cash	48,313		48,313		86,458
Current assets	90,536		90,536		119,733
Non-current assets	1,365,936		1,365,936		1,453,048
Current liabilities	136,826		136,826		74,618
Long- term debt including current portion, net	1,016,324		1,016,324		1,065,369
Non-current liabilities	941,694		941,694		1,035,688
Income Statement
Revenue	41,589	54,021	129,218	176,961
Net income/ (loss)	$ (23,408)	$ (8,105)	$ (69,942)	$ (66,907)
Navios Europe I
Balance sheet
Cash and cash equivalents, including restricted cash					19,185	10,785
Current assets					22,417	15,980
Non-current assets					145,940	169,925
Current liabilities					21,284	18,490
Long- term debt including current portion, net					75,472	86,060
Non-current liabilities					125,283	155,387
Income Statement
Revenue					37,468	40,589	41,437
Net (loss)/ income before non-cash change in fair value of Junior Loan I and Junior Loan II					(20,778)	(2,174)	(1,347)
Net income/ (loss)					9,762	16,137	(1,118)
Navios Europe II
Balance sheet
Cash and cash equivalents, including restricted cash					16,882	16,916
Current assets					28,403	19,487
Non-current assets					195,784	232,363
Current liabilities					25,805	24,126
Long- term debt including current portion, net					109,223	119,234
Non-current liabilities					164,276	184,530
Income Statement
Revenue					38,633	30,893	20,767
Net (loss)/ income before non-cash change in fair value of Junior Loan I and Junior Loan II					22,749	(25,062)	1,673
Net income/ (loss)					(9,086)	$ (34,059)	$ 77,252
Navios Containers
Balance sheet
Cash and cash equivalents, including restricted cash					14,501
Current assets					21,371
Non-current assets					245,440
Current liabilities					49,559
Long- term debt including current portion, net					119,033
Non-current liabilities					76,534
Income Statement
Revenue					39,188
Net (loss)/ income before non-cash change in fair value of Junior Loan I and Junior Loan II					2,638
Net income/ (loss)					$ 2,638

Investments in affiliates and investments in available-for-sale securities - Navios Europe I and Navios Europe II (Details) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 18, 2013 USD ($)	Feb. 18, 2015 USD ($)
Investments In And Advances To Affiliates [Line Items]
Long-term debt	$ 1,599,331	$ 1,643,215		$ 1,599,331	$ 1,643,215	$ 1,682,488	$ 1,651,095	$ 1,581,308
Investments in affiliates	166,888	185,548		166,888	185,548	183,160	160,071	381,746
Portion of the carrying balance of related party loan	34,635			34,635		30,112	23,008
Equity in net earnings of affiliated companies	(4,231)	901		(13,720)	2,208	4,399	(202,779)	61,484
Navios Europe I
Investments In And Advances To Affiliates [Line Items]
Difference between carrying amount of investment and underlying equity in net assets of equity method investee	3,526			3,526		4,034	4,710		$ 6,763
Estimated maximum potential loss	26,207			26,207		23,838	18,268
Investments in affiliates	4,750			$ 4,750		$ 4,750	5,967		$ 4,750
Profit Sharing Arrangement				On an ongoing basis, Navios Europe I is required to distribute cash flows (after payment of operating expenses and amounts due pursuant to the terms of the Senior Loans I) according to a defined waterfall calculation.		On an ongoing basis, Navios Europe I is required to distribute cash flows (after payment of operating expenses and amounts due pursuant to the terms of the Senior Loans I) according to a defined waterfall calculation.
Equity in net earnings of affiliated companies	0	(5)		$ 0	153	$ (1,089)	1,303	$ 1,293
Number of vessels acquired									10
Navios Europe I \| Navios Term Loans I
Investments In And Advances To Affiliates [Line Items]
Investents in affiliates including accrued interest	8,712			8,712		7,924	8,198
Navios Europe I \| Navios Revolving Loans I
Investments In And Advances To Affiliates [Line Items]
Portion of the carrying balance of related party loan	17,496			17,496		15,914	10,070
Navios Europe I \| Navios Revolving Loans I \| Navios Holdings, Navios Acquisition and Navios Partners
Investments In And Advances To Affiliates [Line Items]
Line of credit facility maximum borrowing capacity									$ 24,100
Navios Europe I \| 10 vessels \| Navios Holdings, Navios Acquisition and Navios Partners
Investments In And Advances To Affiliates [Line Items]
Long-term debt									$ 10,000
Navios Europe II
Investments In And Advances To Affiliates [Line Items]
Difference between carrying amount of investment and underlying equity in net assets of equity method investee	6,305			6,305		7,011	7,953			$ 9,419
Estimated maximum potential loss	26,198			26,198		22,463	22,287
Investments in affiliates	6,650			$ 6,650		$ 6,650	5,894			$ 6,650
Profit Sharing Arrangement				On an ongoing basis, Navios Europe II is required to distribute cash flows (after payment of operating expenses, amounts due pursuant to the terms of the Senior Loans II) according to a defined waterfall calculation.		On an ongoing basis, Navios Europe II is required to distribute cash flows (after payment of operating expenses, amounts due pursuant to the terms of the Senior Loans II) according to a defined waterfall calculation.
Equity in net earnings of affiliated companies	523	$ 244		$ 1,485	$ 445	$ 2,456	(14)
Number of vessels acquired								14
Navios Europe II \| Navios Term Loans II
Investments In And Advances To Affiliates [Line Items]
Investents in affiliates including accrued interest	11,886			11,886		10,400	7,944
Navios Europe II \| Navios Revolving Loans II
Investments In And Advances To Affiliates [Line Items]
Portion of the carrying balance of related party loan	$ 14,313			$ 14,313		$ 12,063	$ 14,343
Navios Europe II \| Navios Revolving Loans II \| Navios Holdings, Navios Acquisition and Navios Partners
Investments In And Advances To Affiliates [Line Items]
Line of credit facility maximum borrowing capacity								$ 43,500
Line of Credit Facility, Increase			$ 14,000
Navios Europe II \| 14 Vessels \| Navios Holdings, Navios Acquisition and Navios Partners
Investments In And Advances To Affiliates [Line Items]
Long-term debt								$ 14,000

Investments in affiliates and investments in available-for-sale securities - Navios Containers (Details) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended		3 Months Ended				5 Months Ended	9 Months Ended		12 Months Ended
	Mar. 13, 2018	Feb. 28, 2015	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Mar. 31, 2017	Jun. 08, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments In And Advances To Affiliates [Line Items]
Equity in net (losses)/earnings of affiliated companies			$ (4,231)		$ 901			$ (13,720)	$ 2,208	$ 4,399	$ (202,779)	$ 61,484
Investments in affiliates			166,888		185,548			166,888	185,548	183,160	160,071	381,746
Navios Partners
Investments In And Advances To Affiliates [Line Items]
Partners' Capital Account, Units, Sold in Private Placement				1,370,044		2,040,000
Equity in net (losses)/earnings of affiliated companies			$ 473		473			$ 1,419	1,419	$ 1,892	$ 1,833	$ 2,621
Navios Containers
Investments In And Advances To Affiliates [Line Items]
Investments on the equity	$ 500						$ 5,000
Ownership percentage of Navios Holdings			3.10%					3.10%		3.40%
Equity in net (losses)/earnings of affiliated companies			$ 171		$ 7			$ 415	$ 95	$ 161
Investments in affiliates			6,075					6,075		5,161
Market value of the investment			$ 5,891					$ 5,891		$ 5,581
Navios Containers \| Common units
Investments In And Advances To Affiliates [Line Items]
Partners' Capital Account, Units, Sold in Private Placement							10,057,645
Price per share offered							$ 5
Proceeds from Issuance of Private Placement							$ 50,288
Navios Containers \| Warrants
Investments In And Advances To Affiliates [Line Items]
Ownership interest			1.70%				1.70%	1.70%
Exercise price							$ 5
Warrants And Rights Outstanding Term							5 years
Navios Partners
Investments In And Advances To Affiliates [Line Items]
Proceeds from Issuance of Private Placement		$ 14,967
Navios Partners \| Private placement \| Common units
Investments In And Advances To Affiliates [Line Items]
Partners' Capital Account, Units, Sold in Private Placement		1,120,547
Navios Partners \| Navios Containers
Investments In And Advances To Affiliates [Line Items]
Consolidation Less Than Wholly Owned Subsidiary Parent Ownership Interest Changes Purchase Of Interest By Parent							$ 30,000
Navios Partners \| Navios Containers \| Warrants
Investments In And Advances To Affiliates [Line Items]
Ownership percentage							6.80%

Investments in affiliates and investments in available-for-sale securities - Investments in available-for-sale securities (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Equity Method Investments [Line Items]
Reclassification to earnings			$ 0	$ 345	$ 1,782
Investment in available-for-sale-securities	$ 227	$ 227	238	0
Unrealized gain			2	0
Unrealized loss		$ (11)	$ (2)
Unrealized gain	$ 16
KLC and STX
Schedule Of Equity Method Investments [Line Items]
Consideration received for AFS securities sold				5,303
Korea Line Corporation (''KLC'')
Schedule Of Equity Method Investments [Line Items]
Reclassification to earnings				$ 345	$ 1,783

Description of Business - Related Parties - Navios Europe I (Table) (Details) - Navios Europe I	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Oct. 09, 2013
Related Party Transaction [Line Items]
Percentage of ownership	47.50%
Navios Holdings
Related Party Transaction [Line Items]
Percentage of ownership			47.50%
Percentage of voting stock held	50.00%	50.00%
Navios Acquisition
Related Party Transaction [Line Items]
Percentage of ownership			47.50%
Percentage of voting stock held	50.00%	50.00%
Navios Partners
Related Party Transaction [Line Items]
Percentage of ownership			5.00%
Percentage of voting stock held	0.00%	0.00%
Tanker vessels
Related Party Transaction [Line Items]
Number of vessels	5	5
Container vessels
Related Party Transaction [Line Items]
Number of vessels	5	5

Summary of Significant Accounting Policies - Long Lived Assets and Deferred Costs (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Annual growth factor management fees after 2018		0.30%
Utilization rate of fleet		99.20%
Amortization of deferred drydock and special survey costs		$ 14,727,000	$ 13,768,000	$ 13,340,000
Amortization and write-off of deferred financing costs		6,391,000	5,653,000	4,524,000
Impairment loss	$ (34,000)	50,565,000	0	0
Vessels
Property Plant And Equipment [Line Items]
Scrap value of vessels per LWT		340
Capitalized interest costs		$ 4,764,000	$ 5,843,000	$ 5,154,000
Ocean-going vessels \| Minimum
Property Plant And Equipment [Line Items]
Period of review of special costs of assets		30 months
Ocean-going vessels \| Maximum
Property Plant And Equipment [Line Items]
Period of review of special costs of assets		60 months
Pushboats and barges \| Maximum
Property Plant And Equipment [Line Items]
Period of review of special costs of assets		96 months
One vessel held and used
Property Plant And Equipment [Line Items]
Impairment loss		$ 32,930,000

Summary of Significant Accounting Policies - Goodwill and Other Intangibles - Intangibles Other Than Goodwill and Foreign Currency Translation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2018	Sep. 30, 2017
Acquired Finite Lived Intangible Assets [Line Items]
Goodwill	$ 160,336	$ 160,336	$ 160,336	$ 160,336	$ 160,336
Foreign currency exchange gains/(losses)	(3,000)	$ 1,600	$ 1,646
Shipping Reporting Unit
Acquired Finite Lived Intangible Assets [Line Items]
Goodwill	56,240
One of the favorable lease terms
Acquired Finite Lived Intangible Assets [Line Items]
Impairment loss of intangible assets other than goodwill	$ 3,397
Navios Holdings \| Trade name
Acquired Finite Lived Intangible Assets [Line Items]
Useful life of assets	32 years
Finite lived intangible assets amortization method	straight line
Navios Holdings \| Customer relationships
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets amortization method	straight line
Navios Logistics
Acquired Finite Lived Intangible Assets [Line Items]
Goodwill	$ 104,096
Navios Logistics \| Trade name
Acquired Finite Lived Intangible Assets [Line Items]
Useful life of assets	10 years
Finite lived intangible assets amortization method	straight line

Summary of Significant Accounting Policies - Provisions, Employee Benefits, Income Taxes and Dividends (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Provision for loss making voyages in progress							$ 2,631	$ 3,129
Revenue	$ 141,453	$ 120,555	$ 390,386	$ 334,519			463,049	419,782	$ 480,820
Termination of indemnities liability							1,336	1,127
Dividends paid to common stockholders							0	0	19,325
Dividends paid to preferred stockholders							0	3,681	16,025
Income tax benefit	$ 380	$ 69	$ 1,324	$ 562			$ 3,192	(1,265)	3,154
Severance and retirement compensation plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Description of defined contribution pension and other postretirement plans							The amount of compensation is based on the number of years of service and the amount of remuneration at the date of dismissal or retirement up to a maximum of two years' salary. If the employees remain in the employment of the Company until normal retirement age, they are entitled to retirement compensation which is equal to 40% of the compensation amount that would be payable if they were dismissed at that time. The number of employees that will remain with the Company until retirement age is not known.
Defined Benefit Plan, Funded Percentage							40.00%
Argentina
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Effective Income Tax Rate Continuing Operations							35.00%
Argentina \| Tax Reform
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Effective Income Tax Rate Continuing Operations					25.00%	30.00%
Income tax benefit							$ 2,837
US Retirement Savings Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Description of defined contribution pension and other postretirement plans							The Company sponsors a 401(k) retirement savings plan, which is categorized as a defined contribution plan. The plan is available to full time employees who meet the plan's eligibility requirements. The plan permits employees to make contributions up to 15% of their annual salary with the Company matching up to the first 6%. The Company makes monthly contributions (matching contributions) to the plan based on amounts contributed by employees. Subsequent to making the matching contributions, the Company has no further obligations. The Company may make an additional discretionary contribution annually if such a contribution is authorized by the Board of Directors. The plan is administered by an independent professional firm that specializes in providing such services.
Pooling arrangements
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Revenue							$ 8,041	$ 15,115	$ 1,825
Minimum \| Stock-Based Compensation
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting Period							3 years
Maximum \| Stock-Based Compensation
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting Period							4 years

Summary of Significant Accounting Policies - Convertible Preferred Stock- Cumulative Redeemable Perpetual Preferred Stock (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2018 $ / shares shares	Dec. 31, 2017 $ / shares shares	Dec. 31, 2016 $ / shares
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Par value of preferred stock	$ 0.0001	$ 0.0001	$ 0.0001
Conversion terms of preferred stock		Five years after the issuance date, 30.0% of the then-outstanding shares of Preferred Stock shall automatically convert into shares of common stock at a conversion price equal to $10.00 per share of common stock with the remaining balance of the then-outstanding shares of Preferred Stock being converted into shares of common stock under the same terms 10 years after their issuance date. At any time following the third anniversary from their issuance date, if the closing price of the common stock has been at least $20.00 per share, for 10 consecutive business days, the remaining balance of the then-outstanding preferred shares shall automatically convert at a conversion price equal to $14.00 per share of common stock. The holders of Preferred Stock are entitled, at their option, at any time following their issuance date and prior to their final conversion date, to convert all or any such then-outstanding preferred shares into common stock at a conversion price equal to $14.00 per common stock.
Dividend rate of preferred stock		2.00%
Five years after the issuance date of Convertible Preferred Stock
Percentage of preferred stock converted		30.00%
Convertible Preferred Stock Share Price		$ 10
After the Third Anniversary of the issuance date
Convertible Preferred Stock Share Price		$ 14
Number of consecutive business days		10
After the Third Anniversary of the issuance date \| Minimum
Closing price of the common stock		$ 20
At any time following the issuance date and prior to the final conversion date
Convertible Preferred Stock Share Price		$ 14
American Depositary Shares - The Series G
Number of shares \| shares	2,000,000	2,000,000
Preferred Stock, Liquidation Preference Per Share		$ 2,500
Dividend rate of preferred stock	8.75%	8.75%
Preferred Stock Redemption Terms		Each of the shares represents 1/100th of a share of the Series G, with a liquidation preference of $2,500.00 per share ($25.00 per American Depositary Share). Dividends are payable quarterly in arrears on the Series G at a rate of 8.75% per annum and on the Series H at a rate of 8.625% per annum of the stated liquidation preference. At any time on or after January 28, 2019, the Series G may be redeemed at the Company's option and at any time on or after July 8, 2019, the Series H may be redeemed at the Company's option (and the American Depositary Shares can be caused to be redeemed), in whole or in part, out of amounts legally available therefore, at a redemption price of $2,500.00 per share (equivalent to $25.00 per American Depositary Share) plus an amount equal to all accumulated and unpaid dividends thereon to the date of redemption, whether or not declared. The Company has accounted for these shares as equity.
Sale of Stock- Redemption price per share	$ 25	$ 25
American Depositary Shares - The Series G \| At any time on or after January 28, 2019
Preferred Stock, Liquidation Preference Per Share		2,500
Preferred Stock Redemption Price per American Depositary Share		$ 25
American Depositary Shares - The Series H
Number of shares \| shares	4,800,000	4,800,000
Preferred Stock, Liquidation Preference Per Share		$ 2,500
Dividend rate of preferred stock	8.625%	8.625%
Preferred Stock Redemption Terms		Each of the shares represents 1/100th of a share of the Series G, with a liquidation preference of $2,500.00 per share ($25.00 per American Depositary Share). Dividends are payable quarterly in arrears on the Series G at a rate of 8.75% per annum and on the Series H at a rate of 8.625% per annum of the stated liquidation preference. At any time on or after January 28, 2019, the Series G may be redeemed at the Company's option and at any time on or after July 8, 2019, the Series H may be redeemed at the Company's option (and the American Depositary Shares can be caused to be redeemed), in whole or in part, out of amounts legally available therefore, at a redemption price of $2,500.00 per share (equivalent to $25.00 per American Depositary Share) plus an amount equal to all accumulated and unpaid dividends thereon to the date of redemption, whether or not declared. The Company has accounted for these shares as equity.
Sale of Stock- Redemption price per share	$ 25	$ 25
American Depositary Shares - The Series H \| At any time on or after July 8, 2019
Preferred Stock, Liquidation Preference Per Share		2,500
Preferred Stock Redemption Price per American Depositary Share		$ 25

Cash and Cash Equivalents (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH AND CASH EQUIVALENTS [Abstract]
Cash on hand and at banks		$ 127,625		$ 126,584
Short-term deposits and highly liquid funds		7		9,408
Cash and cash equivalents	$ 132,925	$ 127,632	$ 114,198	$ 135,992	$ 163,412	$ 247,556

Accounts Receivable, Net (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ACCOUNTS RECEIVABLE,NET [Abstract]
Accounts receivable		$ 80,037	$ 85,266
Less: provision for doubtful receivables		(19,706)	(19,437)	$ (18,278)	$ (18,464)
Accounts receivable, net	$ 56,125	$ 60,331	$ 65,829

Prepaid Expenses and Other Current Assets (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
PREPAID EXPENSES AND OTHER CURRENT ASSETS [Abstract]
Prepaid voyage and operating costs		$ 8,022	$ 8,352
Claims receivable		12,307	9,822
Prepaid other taxes		4,520	4,279
Advances for working capital purposes		18	4,486
Other		2,516	1,957
Total prepaid expenses and other current assets	$ 34,697	$ 27,383	$ 28,896

Vessels, Port Terminal and Other Fixed Assets, Net - Navios Logistics (Details) € in Thousands, $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 EUR (€)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 EUR (€)	May 18, 2017 USD ($)	Feb. 28, 2017 USD ($)	Jun. 03, 2016 USD ($)
Property Plant And Equipment [Line Items]
Purchase price obligation			$ 0		$ 17,617
Payments for construction in process	$ 13,344	$ 28,865	36,589		86,911	$ 26,713
Repayments of obligations under capital leases	0	12,374	12,374		3,032	1,501
Vessels, port terminals and other fixed assets, net	1,694,429		1,809,225		1,821,101
Prepaid expenses and other current assets	34,697		27,383		28,896
Other long term assets	42,479		37,801		2,647
Gain on sale of assets			1,064		0	0
Property Plant And Equipment Transfers And Changes	$ 49,421	$ 137,357	$ 137,357		0	$ 0
Ferni H
Property Plant And Equipment [Line Items]
Vessel Capacity			16,871 dwt	16,871 dwt
San San H
Property Plant And Equipment [Line Items]
Vessel Capacity			16,871 dwt	16,871 dwt
Ferni H and San San H
Property Plant And Equipment [Line Items]
Repayments of obligations under capital leases					3,032
Vessel acquisition cost								$ 11,239
Three new pushboats, price per each
Property Plant And Equipment [Line Items]
Total purchase price										$ 7,344
Payments for construction in process			$ 30,708		16,156
Date of expected delivery			February 2018	February 2018
Three new pushboats, price per each \| Navios Logistics
Property Plant And Equipment [Line Items]
Payments for construction in process			$ 30,708
Date of expected delivery	Q1 2018
Capitalized interest costs	$ 3,874
Property Plant And Equipment Transfers And Changes	$ 32,032
Expansion of its dry port
Property Plant And Equipment [Line Items]
Payments for construction in process					120,735
Capitalized interest costs			9,971		$ 6,862
Vessels, port terminals and other fixed assets, net			137,357
River and estuary tanker
Property Plant And Equipment [Line Items]
Total purchase price			14,854				€ 12,400
Payments for construction in process			$ 6,141
Date of expected delivery			Q2 2018	Q2 2018
Capitalized interest costs			$ 205
River and estuary tanker \| Shipbuilder
Property Plant And Equipment [Line Items]
Percentage financed by third party			50.00%	50.00%
River and estuary tanker \| Maximum
Property Plant And Equipment [Line Items]
Amount financed by third party			$ 7,427	€ 6,200
River and estuary tanker \| Navios Logistics
Property Plant And Equipment [Line Items]
Payments for construction in process			6,141
Date of expected delivery	Q3 2018
Capitalized interest costs	$ 628
Property Plant And Equipment Transfers And Changes	17,389
Formosa and San Lorenzo
Property Plant And Equipment [Line Items]
Vessel sale price									$ 1,109
Prepaid expenses and other current assets			318
Other long term assets			500
Gain on sale of assets			1,075
Formosa and San Lorenzo \| Navios Logistics
Property Plant And Equipment [Line Items]
Vessel sale price									$ 1,109
Covers for Dry Barges
Property Plant And Equipment [Line Items]
Total purchase price			1,115
Payments for construction in process			629
Covers for Dry Barges \| Navios Logistics
Property Plant And Equipment [Line Items]
Total purchase price			1,115
Cash consideration	$ 1,115
Payments for construction in process			$ 629

Intangible Assets/Liabilities Other Than Goodwill (Table) (Details) - USD ($)
$ in Thousands

Sep. 30, 2018

Dec. 31, 2017

Dec. 31, 2016

Acquired Finite Lived Intangible Assets [Line Items]

$ 190,212

^[1]

$ 200,610

(77,924)

(73,790)

10,398

Acquired Finite Lived Intangible Assets [Line Items]

$ 112,288

116,422

Trade name

100,420

$ 100,420

(45,156)

(41,303)

Port terminal operating rights

55,264

59,117

Acquired Finite Lived Intangible Assets [Line Items]

53,152

(10,889)

(10,162)

Acquired Finite Lived Intangible Assets [Line Items]

42,263

42,990

Customer relationships

35,490

(17,745)

(15,971)

Acquired Finite Lived Intangible Assets [Line Items]

17,745

19,519

Favorable lease terms

11,548

82,485

(6,359)

(10,398)

(70,937)

Acquired Finite Lived Intangible Assets [Line Items]

1,150

5,189

Total Intangible assets

200,610

271,547

(73,790)

(73,795)

(10,398)

(70,937)

Acquired Finite Lived Intangible Assets [Line Items]

$ 116,422

126,815

Unfavorable lease terms

(24,721)

24,721

Acquired Finite Lived Intangible Assets [Line Items]

Total

246,826

(73,795)

(46,216)

$ 126,815

[1]	As of both September 30, 2018 and December 31, 2017, intangible assets associated with the favorable lease terms included an amount of $1,150 related to purchase options for the vessels.

Intangible Assets/Liabilities Other Than Goodwill - Amortization Expense (Table) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Expense and Write Offs	$ 1,400	$ 1,775	$ 4,134	$ 5,220
Trade name
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Expense and Write Offs					$ 3,853	$ 3,902	$ 3,811
Port terminal operating rights
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Expense and Write Offs					727	706	1,006
Customer relationships
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Expense and Write Offs					1,775	1,775	1,775
Favorable lease terms
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Expense and Write Offs					4,038	17,260	32,444
Unfavorable lease terms
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Expense and Write Offs					0	(7,526)	(14,615)
Total
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Expense and Write Offs					$ 10,393	$ 16,117	$ 24,420

Intangible Assets/Liabilities Other Than Goodwill - Amortization Schedule (Table) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Acquired Finite Lived Intangible Assets [Line Items]
Within one year		$ 5,571
Year Two		5,571
Year Three		5,578
Year Four		5,571
Year Five		5,571
Thereafter		87,410
Total amortization	$ 111,138	115,272
Year One	5,581
Year Two	5,588
Year Three	5,581
Year Four	5,581
Year Five	5,581
Thereafter	$ 83,226
Trade name
Acquired Finite Lived Intangible Assets [Line Items]
Within one year		2,811
Year Two		2,811
Year Three		2,818
Year Four		2,811
Year Five		2,811
Thereafter		41,202
Total amortization		55,264
Port terminal operating rights
Acquired Finite Lived Intangible Assets [Line Items]
Within one year		985
Year Two		985
Year Three		985
Year Four		985
Year Five		985
Thereafter		37,338
Total amortization		42,263
Customer relationships
Acquired Finite Lived Intangible Assets [Line Items]
Within one year		1,775
Year Two		1,775
Year Three		1,775
Year Four		1,775
Year Five		1,775
Thereafter		8,870
Total amortization		$ 17,745

Intangible Assets/Liabilities Other Than Goodwill - Additional Details (Details) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

11 Months Ended

12 Months Ended

Sep. 30, 2018

Sep. 30, 2017

Sep. 30, 2018

Sep. 30, 2017

Dec. 15, 2014

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Intangible asset

$ 112,288

$ 116,422

$ 126,815

190,212

^[1]

190,212

^[1]

200,610

77,924

73,790

Amortization of intangible assets

10,398

1,400

$ 1,775

4,134

$ 5,220

Favorable lease terms

Intangible asset

$ 1,150

1,150

1,180

10,398

70,937

Gain / (loss) resulting from favorable lease terms written off

7,001

57,930

$ (3,397)

(13,007)

Unfavorable lease terms

24,721

Gain / (loss) resulting from favorable lease terms written off

17,406

$ 7,315

Two Companies | Navios Logistics

Date of acquisition

Dec. 15, 2014

Total consideration

$ 17,000

Deferred Payment For Acquisition Intangible Assets

$ 6,800

$ 10,200

[1]	As of both September 30, 2018 and December 31, 2017, intangible assets associated with the favorable lease terms included an amount of $1,150 related to purchase options for the vessels.

Investments in affiliates and investments in available-for-sale securities (Details) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended		3 Months Ended						9 Months Ended		12 Months Ended
	Feb. 21, 2018	Feb. 28, 2015	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Mar. 31, 2017	Mar. 20, 2017	Mar. 17, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Equity Method Investments [Line Items]
Payments to acquire common stock									$ 6,278	$ 7,638	$ 7,638	$ 0	$ 22,846
Equity in net earnings of affiliated companies			$ (4,231)		$ 901				(13,720)	2,208	4,399	(202,779)	61,484
Investments in affiliates			166,888		185,548				166,888	185,548	183,160	160,071	381,746
Dividends received									4,379	$ 3,649	7,298	0	18,244
Other than temporary impairment loss on investments												228,026
Navios Partners
Schedule Of Equity Method Investments [Line Items]
General partner interest of Navios Holdings	2.00%			2.00%		2.00%	2.00%			2.00%
Common Units issued in public offering						1,200,442
Payments to acquire investment	$ 714			$ 64		$ 110	$ 2,048			$ 12
Number of shares issued-common stock	18,422,000						47,795,000
Equity in net earnings of affiliated companies			$ 473		473				$ 1,419	$ 1,419	$ 1,892	1,833	2,621
Private placement of units to Navios Holdings				1,370,044		2,040,000
Partners capital account units acquisitions				27,960		66,131	975,408			7,376
Issuance of common stock	$ 5,000
Price per common unit							$ 2.1
Navios Revolving Loans I Transfer
Schedule Of Equity Method Investments [Line Items]
Long-term liability recognized								$ 33,473
Proceeds from transfer of debt								$ 4,050
Navios Revolving Loans I Transfer \| Navios Partners
Schedule Of Equity Method Investments [Line Items]
General partner interest of Navios Holdings								2.00%
Payments to acquire investment								$ 468
Number of shares issued-common stock								13,076,923
Consideration equity component								$ 29,423
Partners capital account units acquisitions								266,876
Navios Partners
Schedule Of Equity Method Investments [Line Items]
Common Units issued in public offering		4,600,000
Proceeds From Issuance Of Common Limited Partners Units		$ 60,214
Proceeds from private placement of units to Navios Holdings		$ 14,967
Private placement \| Common units \| Navios Partners
Schedule Of Equity Method Investments [Line Items]
Private placement of units to Navios Holdings		1,120,547
Private placement \| General partner units \| Navios Partners
Schedule Of Equity Method Investments [Line Items]
Private placement of units to Navios Holdings		22,868
Navios Partners
Schedule Of Equity Method Investments [Line Items]
General partner interest of Navios Holdings									2.00%		2.00%
Payments to acquire common stock		$ 1,229
General Partner units held by Navios Holdings			3,420,203						3,420,203		3,016,284
Common units held by Navios Holdings			31,053,233						31,053,233		28,421,233
Difference between carrying amount of investment and underlying equity in net assets of equity method investee			$ 81,777						$ 81,777		$ 98,608	112,417
Equity in net earnings of affiliated companies			4,915		3,360				14,363	$ 6,670	12,570	(5,979)	15,462
Investments in affiliates			84,116						84,116		66,773	24,033
Dividends received			$ 690		0				$ 1,379	0	$ 0	0	27,993
Ownership percentage of Navios Holdings			20.20%						20.20%		20.80%
Market value of the investment			$ 60,329						$ 60,329		$ 74,193
Other than temporary impairment loss on investments												83,596
Acropolis
Schedule Of Equity Method Investments [Line Items]
Investments in affiliates			123						123		228	105
Dividends received			$ 0		0				$ 170	55	$ 55	85	454
Ownership percentage of Navios Holdings			35.00%						35.00%		35.00%
Ownership Interest									50.00%		50.00%
Profit Sharing Arrangement									Navios Holdings has a 50% interest in Acropolis, a brokerage firm for freight and shipping charters. Although Navios Holdings owns 50% of Acropolis' stock, Navios Holdings agreed with the other shareholder that the earnings and amounts declared by way of dividends will be allocated 35% to the Company with the balance to the other shareholder.		Navios Holdings has a 50% interest in Acropolis, a brokerage firm for freight and shipping charters. Although Navios Holdings owns 50% of Acropolis' stock, Navios Holdings agreed with the other shareholder that the earnings and amounts declared by way of dividends will be allocated 35% to the Company with the balance to the other shareholder.
Navios Acquisition
Schedule Of Equity Method Investments [Line Items]
Difference between carrying amount of investment and underlying equity in net assets of equity method investee			$ 114,741						$ 114,741		$ 113,597	140,131
Equity in net earnings of affiliated companies			(9,856)		(2,744)				(30,048)	(5,319)	(9,875)	29,801	43,299
Investments in affiliates			65,164						65,164		99,590	124,062
Dividends received			$ 1,460		$ 3,649				$ 4,379	$ 10,947	$ 14,595	14,595	$ 18,244
Ownership percentage of Navios Holdings			48.60%						48.60%		46.20%
Percentage of voting stock of Navios Holdings in Navios Acquisition									45.30%		42.90%
Market value of the investment			$ 37,233						$ 37,233		$ 81,005
Other than temporary impairment loss on investments												$ 144,430

Borrowings - Senior and Ship Mortgage Notes Navios Holdings and Navios Logistics (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		10 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Oct. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Amount used for repayment of debt						$ 48,600
Gain/ (Loss) on bond and debt extinguishment	$ 6,464	$ 0	$ 6,464	$ 1,715		(981)	$ 29,187	$ 0
Dividends paid						0	3,681	$ 35,350
Dividends paid to the non controlling shareholders						25,323
Navios Logistics
Debt Instrument [Line Items]
Face amount at issuance date	166,853		$ 166,853
Minimum \| Navios Logistics
Debt Instrument [Line Items]
Maturity date			Aug. 31, 2020
Maximum \| Navios Logistics
Debt Instrument [Line Items]
Maturity date			Nov. 30, 2024
2022 Senior Secured Notes
Debt Instrument [Line Items]
Face amount at issuance date	$ 305,000		$ 305,000			$ 305,000
Issuance date/Date of agreement			Nov. 21, 2017			Nov. 21, 2017
Debt instrument, issuance price percentage			97.00%			97.00%
Fixed interest rate	11.25%		11.25%			11.25%
Gain/ (Loss) on bond and debt extinguishment						$ (2,695)
2022 Senior Secured Notes \| Upon occurrence of certain change of control events
Debt Instrument [Line Items]
Redemption price percentage			101.00%
2022 Senior Secured Notes \| On or after November 21, 2017
Debt Instrument [Line Items]
Redemption price percentage			108.438%			108.438%
Senior Notes due 2019
Debt Instrument [Line Items]
Face amount at issuance date	$ 350,000		$ 350,000			$ 350,000
Issuance date/Date of agreement			Jan. 28, 2011			Jan. 28, 2011
Amount oustanding						$ 0	291,094
Fixed interest rate	8.125%		8.125%			8.125%
Repurchase of notes					$ 58,906
Repurchase of senior notes - cash consideration					30,671
Gain/ (Loss) on bond and debt extinguishment					$ 27,670
2022 Notes
Debt Instrument [Line Items]
Face amount at issuance date	$ 650,000		$ 650,000			$ 650,000
Issuance date/Date of agreement			Nov. 29, 2013			Nov. 29, 2013
Amount oustanding	$ 614,339		$ 614,339			$ 650,000	650,000
Fixed interest rate	7.375%		7.375%			7.375%
Repurchase of notes			$ 35,661
Repurchase of senior notes - cash consideration			28,796
Gain/ (Loss) on bond and debt extinguishment			$ 6,464
2022 Notes \| Upon occurrence of certain change of control events
Debt Instrument [Line Items]
Redemption price percentage			101.00%			101.00%
2022 Notes \| On or after January 15, 2017
Debt Instrument [Line Items]
Redemption price percentage			105.531%			105.531%
2022 Logistics Senior Notes
Debt Instrument [Line Items]
Amount oustanding	$ 375,000		$ 375,000			$ 375,000	$ 375,000
2022 Logistics Senior Notes \| Navios Logistics
Debt Instrument [Line Items]
Face amount at issuance date	$ 375,000		$ 375,000			$ 375,000
Issuance date/Date of agreement			Apr. 22, 2014			Apr. 22, 2014
Fixed interest rate	7.25%		7.25%			7.25%
Maturity date			May 01, 2022			May 01, 2022
Maximum dividend percentage						6.00%
2022 Logistics Senior Notes \| Navios Logistics \| Upon occurrence of certain change of control events
Debt Instrument [Line Items]
Redemption price percentage			101.00%			101.00%
2022 Logistics Senior Notes \| All subsidiaries of Navios Logistics
Debt Instrument [Line Items]
Percentage of ownership						100.00%
2022 Logistics Senior Notes \| On or after May 1, 2017 \| Navios Logistics
Debt Instrument [Line Items]
Redemption price percentage			105.438%			105.438%
Navios Logistics Alpha Bank Loan
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity						$ 14,000
Interest Rate						LIBOR (90 days) plus 315 basis points
Fixed interest rate						3.15%
Duration of loan						5 years
Repayment installments						20
Repayment frequency						quarterly
Balloon payment on the last repayment date						$ 7,000
Navios Logistics Term Loan B Facility
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity						$ 100,000
Interest Rate						LIBOR plus 475 basis points
Fixed interest rate						4.75%
Duration of loan						4 years
Debt amortization percentage						1.00%
Dividends paid						$ 70,000
Dividends paid to Navios Holdings						44,677
Dividends paid to the non controlling shareholders						$ 25,323
Line of credit facility issuance date						Nov. 03, 2017
Debt Instrument Collateral						5 tanker vessels

Fair Value of Financial Instruments - Non-Recurring Measurements (Table) (Details) - USD ($)
$ in Thousands

Sep. 30, 2018

Dec. 31, 2017

Dec. 31, 2016

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Investments in available-for-sale securities

$ 132,925

$ 127,632

$ 135,992

Restricted cash

10,056

6,558

5,386

227

238

Loan receivable from affiliate companies

34,635

30,112

23,008

Long-term receivable from affiliate companies

11,105

Capital lease obligations, including current portion

(1,112,673)

(1,181,838)

(974,170)

(17,617)

Long-term debt, including current portion

(335,301)

(389,332)

(308,080)

Loan payable to affiliate company

(51,240)

Long-term payable to affiliate companies

(86,005)

(76,872)

(6,399)

Scenario, Previously Reported [Member]

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Fair Value, Measurements, Nonrecurring

(1,181,838)

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Loan receivable from affiliate companies

132,925

127,632

135,992

Restricted cash

10,056

6,558

5,386

34,635

^[1]

30,112

^[1]

23,008

Long-term receivable from affiliate companies

11,105

Capital lease obligations, including current portion

(1,112,673)

(1,181,383)

(974,170)

(17,617)

Long-term debt, including current portion

(335,301)

^[2]

(389,332)

^[2]

(308,080)

Loan payable to affiliate company

(51,240)

Long-term payable to affiliate companies

(86,005)

^[1]

(76,872)

^[1]

(6,399)

Fair Value, Measurements, Nonrecurring | Scenario, Previously Reported [Member]

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

(Level I) | Fair Value, Measurements, Nonrecurring

(1,181,838)

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

132,925

127,632

135,992

Restricted cash

10,056

6,558

5,386

(Level I) | Fair Value, Measurements, Nonrecurring | Scenario, Previously Reported [Member]

(1,112,673)

(1,181,838)

(974,170)

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]