Revenue Business Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenues	$ 1,909,482	$ 1,921,507	$ 2,271,603
Rovs Member
Disaggregation of Revenue [Line Items]
Revenues	394,801	393,655	522,121
Subsea Products Member
Disaggregation of Revenue [Line Items]
Revenues	515,000	625,513	692,030
Subsea Projects Member
Disaggregation of Revenue [Line Items]
Revenues	329,163	291,993	472,979
Inspection Member
Disaggregation of Revenue [Line Items]
Revenues	253,886	236,778	275,397
Oil And Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,492,850	1,547,939	1,962,527
Advanced Technologies Member
Disaggregation of Revenue [Line Items]
Revenues	$ 416,632	$ 373,568	$ 309,076