Operations by Business Segment and Geographic Area Operations by Business Segment and Geographic Areas - Schedule of Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 3,023,950	$ 3,130,315
Property, Plant and Equipment, Net	1,064,204	1,153,258
Goodwill	455,599	443,551
Oil And Gas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	2,334,264	2,459,634
Property, Plant and Equipment, Net	1,041,668	1,127,991
Goodwill	433,757	421,709
ROVs [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	650,832	755,894
Property, Plant and Equipment, Net	420,088	485,063
Goodwill	24,777	24,406
Subsea Products [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	788,586	833,919
Property, Plant and Equipment, Net	329,486	344,973
Goodwill	103,128	99,336
Subsea Projects [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	626,791	608,411
Property, Plant and Equipment, Net	272,649	273,384
Goodwill	155,292	154,823
Asset Integrity [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	268,055	261,410
Property, Plant and Equipment, Net	19,445	24,571
Goodwill	150,560	143,144
Advanced Technologies [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	129,185	101,756
Property, Plant and Equipment, Net	10,850	12,057
Goodwill	21,842	21,842
Corporate and Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	560,501	568,925
Property, Plant and Equipment, Net	$ 11,686	$ 13,210