Revenue - Disaggregation of Revenue (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]
Revenues	$ 495,781	$ 493,886	$ 478,674	$ 989,667	$ 895,087
Remotely Operated Vehicles [Member]
Segment Reporting Information [Line Items]
Revenues	120,363	100,346	107,426	220,709	193,020
Subsea Products [Member]
Segment Reporting Information [Line Items]
Revenues	138,910	128,844	121,704	267,754	248,392
Subsea Projects [Member]
Segment Reporting Information [Line Items]
Revenues	75,104	89,728	78,036	164,832	134,896
Asset Integrity [Member]
Segment Reporting Information [Line Items]
Revenues	61,156	60,689	67,422	121,845	128,710
Oil and Gas [Member]
Segment Reporting Information [Line Items]
Revenues	395,533	379,607	374,588	775,140	705,018
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Revenues	$ 100,248	$ 114,279	$ 104,086	$ 214,527	$ 190,069