Major Customers and Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating Revenues	$ 170,941		$ 141,837		$ 174,453
Direct Costs and Expenses	127,406		91,145		109,523
Direct Vessel (Loss) Profit	43,535		50,692		64,930
Lease expense	6,085		7,525		15,840
Administrative and general	37,639		40,051		39,791
Depreciation and amortization	57,395		57,167		57,166
Other Costs and Expenses	101,119		104,743		112,797
Gains (Losses) on Asset Dispositions and Impairments, Net	20,436		(17,588)		(6,461)
Operating loss	(37,148)		(71,639)		(54,328)
Historical cost	1,025,284	[1]	1,012,873	[1]	899,024
Accumulated depreciation	(317,297)		(291,538)		(308,917)
Property and equipment	707,987		721,335		590,107
Total Assets	823,065	[2]	861,806	[2]	817,926	[3]
Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	159,835		133,454		157,052
Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues	4,033		2,855		5,131
Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	7,073		5,528		12,270
Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	59,920		48,348		55,975
Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	24,117		14,661		21,401
Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	6,347		4,269		5,848
Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	8,667		5,763		5,622
Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	12,033		8,128		10,622
Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	16,322		9,976		10,055
UNITED STATES
Segment Reporting Information [Line Items]
Operating Revenues	20,643		15,205		44,323
Direct Costs and Expenses	18,796		16,206		35,367
Direct Vessel (Loss) Profit	1,847		(1,001)		8,956
Lease expense	2,621		4,272		10,894
Depreciation and amortization	15,712		21,427		21,947
Historical cost	253,426		257,592		297,392
Accumulated depreciation	(127,547)		(134,391)		(157,514)
Property and equipment	125,879		123,201		139,878
Total Assets	148,753	[2]	164,656	[2]	224,229	[3]
UNITED STATES | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	15,487		9,873		38,955
UNITED STATES | Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues	1,549		2,910		1,562
UNITED STATES | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	3,607		2,422		3,806
UNITED STATES | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	8,836		10,065		17,491
UNITED STATES | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,394		1,655		7,583
UNITED STATES | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	2,082		1,167		4,594
UNITED STATES | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	2,632		1,774		2,370
UNITED STATES | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,204		1,172		2,936
UNITED STATES | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	648		373		393
Africa and Europe
Segment Reporting Information [Line Items]
Operating Revenues	42,930		47,533		57,730
Direct Costs and Expenses	33,111		27,463		33,711
Direct Vessel (Loss) Profit	9,819		20,070		24,019
Lease expense	1,281		3,038		4,763
Depreciation and amortization	12,856		13,664		12,614
Historical cost	223,039		262,998		251,652
Accumulated depreciation	(71,820)		(68,486)		(62,125)
Property and equipment	151,219		194,512		189,527
Total Assets	167,185	[2]	227,894	[2]	226,071	[3]
Africa and Europe | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	44,268		47,723		52,325
Africa and Europe | Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues			(55)
Africa and Europe | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	(1,338)		(135)		5,405
Africa and Europe | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	13,903		13,397		17,327
Africa and Europe | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	6,772		5,643		5,288
Africa and Europe | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,159		2,014		493
Africa and Europe | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,353		1,806		1,492
Africa and Europe | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	4,109		3,260		3,726
Africa and Europe | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	5,815		1,343		5,385
Middle East and Asia
Segment Reporting Information [Line Items]
Operating Revenues	53,672		54,209		55,981
Direct Costs and Expenses	43,629		35,497		31,928
Direct Vessel (Loss) Profit	10,043		18,712		24,053
Lease expense	472		170		173
Depreciation and amortization	17,985		16,595		16,400
Historical cost	340,225		361,514		292,446
Accumulated depreciation	(85,683)		(75,349)		(73,039)
Property and equipment	254,543		286,165		219,407
Total Assets	256,533	[2]	289,314	[2]	250,890	[3]
Middle East and Asia | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	53,146		52,052		54,312
Middle East and Asia | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	526		2,157		1,669
Middle East and Asia | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	22,191		18,188		16,698
Middle East and Asia | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	6,701		5,232		7,182
Middle East and Asia | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	2,639		759		600
Middle East and Asia | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	2,481		1,721		1,449
Middle East and Asia | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,459		2,706		2,904
Middle East and Asia | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	6,158		6,891		3,095
Latin America
Segment Reporting Information [Line Items]
Operating Revenues	53,696		24,890		16,419
Direct Costs and Expenses	31,870		11,979		8,517
Direct Vessel (Loss) Profit	21,826		12,911		7,902
Lease expense	1,711		45		10
Depreciation and amortization	10,842		5,481		6,205
Historical cost	208,594		130,769		57,534
Accumulated depreciation	(32,247)		(13,312)		(16,239)
Property and equipment	176,347		117,457		41,295
Total Assets	250,594	[2]	179,942	[2]	116,736	[3]
Latin America | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	46,934		23,806		11,460
Latin America | Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues	2,484				3,569
Latin America | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	4,278		1,084		1,390
Latin America | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	14,990		6,698		4,459
Latin America | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	7,250		2,131		1,348
Latin America | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	467		329		161
Latin America | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	2,201		462		311
Latin America | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,261		990		1,056
Latin America | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	$ 3,701		$ 1,369		$ 1,182

[1] Includes property and equipment acquired in business acquisitions at acquisition date fair value, and net of the impact of recognized impairment charges.

[2] Total assets exclude $89.4 million of corporate assets. 

[3] Total assets exclude $145.5 million of corporate assets, and $45.7 million of discontinued operations.