Business Segment Information - Financial Data By Business Segment (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Goodwill	$ 74,946,000		$ 405,079,000		$ 74,946,000
Write-off Equipment and Intangibles					7,300,000
Inventory Write-down					0	$ 0
Impairment of Long-Lived Assets Held-for-use	0	$ 68,763,000				0
Goodwill, Impairment Loss	0		15,000,000	$ 0	$ 303,005,000	0
Document Period End Date					Jun. 30, 2020
Other adjustments to Income from continuing operations					$ 386,000,000
Other Asset Impairment Charges					69,000,000
Impairment property plant equipment		51,578,000
Depreciation	38,000,000	43,000,000		49,000,000	81,000,000	97,000,000
Revenue	427,216,000	536,668,000		495,781,000	963,884,000	989,667,000
Income (Loss) from Operations	(5,182,000)	(380,757,000)		(9,635,000)	(385,939,000)	(31,349,000)
Depreciation and amortization, including goodwill impairment	38,698,000	356,196,000		50,304,000	394,894,000	102,790,000
Amortization of Intangible Assets	800,000	2,600,000		1,800,000	3,400,000	5,600,000
Oil and Gas [Member]
Segment Reporting Information [Line Items]
Revenue	333,836,000	427,205,000		395,533,000	761,041,000	775,140,000
Income (Loss) from Operations	13,290,000	(337,523,000)		14,886,000	(324,233,000)	18,007,000
Depreciation and amortization, including goodwill impairment	37,703,000	342,910,000		48,357,000	380,613,000	98,854,000
Remotely Operated Vehicles [Member]
Segment Reporting Information [Line Items]
Goodwill	23,935,000		24,423,000		23,935,000
Other adjustments to Income from continuing operations					700,000
Revenue	98,778,000	111,780,000		120,363,000	210,558,000	220,709,000
Income (Loss) from Operations	5,975,000	9,066,000		8,688,000	15,041,000	10,106,000
Depreciation and amortization, including goodwill impairment	22,892,000	25,725,000		26,871,000	48,617,000	54,861,000
Subsea Products [Member]
Segment Reporting Information [Line Items]
Goodwill	40,557,000		99,409,000		40,557,000
Goodwill, Impairment Loss		51,000,000			51,000,000
Other adjustments to Income from continuing operations					108,000,000
Revenue	130,655,000	194,838,000		138,910,000	325,493,000	267,754,000
Income (Loss) from Operations	9,068,000	(91,858,000)		7,413,000	(82,790,000)	6,937,000
Depreciation and amortization, including goodwill impairment	10,024,000	62,454,000		12,366,000	72,478,000	25,357,000
Subsea Projects [Member]
Segment Reporting Information [Line Items]
Goodwill			131,768,000
Goodwill, Impairment Loss		130,000,000			130,000,000
Other adjustments to Income from continuing operations					146,000,000
Revenue	56,326,000	61,455,000		75,104,000	117,781,000	164,832,000
Income (Loss) from Operations	845,000	(145,290,000)		87,000	(144,445,000)	2,979,000
Depreciation and amortization, including goodwill impairment	4,597,000	143,346,000		7,550,000	147,943,000	15,432,000
Asset Integrity [Member]
Segment Reporting Information [Line Items]
Goodwill			127,637,000
Goodwill, Impairment Loss		111,000,000			111,000,000
Other adjustments to Income from continuing operations					112,000,000
Revenue	48,077,000	59,132,000		61,156,000	107,209,000	121,845,000
Income (Loss) from Operations	(2,598,000)	(109,441,000)		(1,302,000)	(112,039,000)	(2,015,000)
Depreciation and amortization, including goodwill impairment	190,000	111,385,000		1,570,000	111,575,000	3,204,000
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Goodwill	10,454,000		21,842,000		10,454,000
Goodwill, Impairment Loss		11,000,000			11,000,000
Other adjustments to Income from continuing operations					18,000,000
Revenue	93,380,000	109,463,000		100,248,000	202,843,000	214,527,000
Income (Loss) from Operations	9,707,000	(10,585,000)		7,241,000	(878,000)	16,840,000
Depreciation and amortization, including goodwill impairment	634,000	12,178,000		765,000	12,812,000	1,595,000
Other Segments [Member]
Segment Reporting Information [Line Items]
Other adjustments to Income from continuing operations					6,600,000
Unallocated Expenses [Member]
Segment Reporting Information [Line Items]
Income (Loss) from Operations	(28,179,000)	(32,649,000)		(31,762,000)	(60,828,000)	(66,196,000)
Depreciation and amortization, including goodwill impairment	361,000	$ 1,108,000		$ 1,182,000	1,469,000	$ 2,341,000
Energy Service [Member]
Segment Reporting Information [Line Items]
Goodwill	$ 64,492,000		$ 383,237,000		$ 64,492,000