Business Segment Information - Financial Data By Business Segment (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)			$ 7,600
Revenue	$ 495,781	$ 493,886	478,674	$ 989,667	$ 895,087
Income (Loss) from Operations	(9,635)	(21,714)	(19,637)	(31,349)	(46,786)
Depreciation and amortization	50,304	52,486	59,843	102,790	113,971
Oil and Gas [Member]
Segment Reporting Information [Line Items]
Revenue	395,533	379,607	374,588	775,140	705,018
Income (Loss) from Operations	14,886	3,121	(164)	18,007	(1,487)
Depreciation and amortization	48,357	50,497	58,072	98,854	109,900
Remotely Operated Vehicles [Member]
Segment Reporting Information [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)			600
Revenue	120,363	100,346	107,426	220,709	193,020
Income (Loss) from Operations	8,688	1,418	4,542	10,106	2,144
Depreciation and amortization		27,990		54,861	55,911
Subsea Products [Member]
Segment Reporting Information [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)			1,500
Revenue	138,910	128,844	121,704	267,754	248,392
Income (Loss) from Operations	7,413	(476)	2,295	6,937	4,050
Depreciation and amortization		12,991		25,357	28,939
Subsea Projects [Member]
Segment Reporting Information [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)			5,500
Revenue	75,104	89,728	78,036	164,832	134,896
Income (Loss) from Operations	87	2,892	(10,358)	2,979	(12,717)
Depreciation and amortization		7,882		15,432	21,366
Asset Integrity [Member]
Segment Reporting Information [Line Items]
Revenue	61,156	60,689	67,422	121,845	128,710
Income (Loss) from Operations	(1,302)	(713)	3,357	(2,015)	5,036
Depreciation and amortization		1,634		3,204	3,684
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Revenue	100,248	114,279	104,086	214,527	190,069
Income (Loss) from Operations	7,241	9,599	7,886	16,840	9,554
Depreciation and amortization		830		1,595	1,503
Unallocated Expenses [Member]
Segment Reporting Information [Line Items]
Income (Loss) from Operations	$ (31,762)	(34,434)	$ (27,359)	(66,196)	(54,853)
Depreciation and amortization		$ 1,159		$ 2,341	$ 2,568

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

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