Operations by Business Segment and Geographic Area - Financial Data By Business Segment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting Information [Line Items]
Revenue	$ 2,192,663	$ 1,917,045	$ 1,822,081
Income from Operations	334,831	309,500	292,116
Depreciation, Depletion and Amortization, Nonproduction	151,227	153,651	122,945
Income (Loss) from Equity Method Investments	3,801	2,078	3,242
Oil And Gas [Member]
Segment Reporting Information [Line Items]
Revenue	1,959,299	1,682,345	1,627,701
Income from Operations	430,111	393,050	370,056
Depreciation, Depletion and Amortization, Nonproduction	145,101	144,112	114,960
ROVs [Member]
Segment Reporting Information [Line Items]
Revenue	755,033	662,105	649,228
Income from Operations	224,705	211,725	207,683
Depreciation, Depletion and Amortization, Nonproduction	100,089	86,232	68,022
Subsea Products [Member]
Segment Reporting Information [Line Items]
Revenue	770,212	549,233	487,726
Income from Operations	142,184	108,522	60,526
Depreciation, Depletion and Amortization, Nonproduction	31,299	27,956	24,133
Income (Loss) from Equity Method Investments	(136)	0	0
Subsea Projects [Member]
Segment Reporting Information [Line Items]
Revenue	167,477	247,538	274,607
Income from Operations	32,662	46,910	75,404
Depreciation, Depletion and Amortization, Nonproduction	8,024	25,826	19,011
Income (Loss) from Equity Method Investments	3,937	2,078	3,242
Asset Integrity [Member]
Segment Reporting Information [Line Items]
Revenue	266,577	223,469	216,140
Income from Operations	30,560	25,893	26,443
Depreciation, Depletion and Amortization, Nonproduction	5,689	4,098	3,794
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Revenue	233,364	234,700	194,380
Income from Operations	16,661	16,934	12,366
Depreciation, Depletion and Amortization, Nonproduction	3,134	4,588	2,526
Unallocated Expenses [Member]
Segment Reporting Information [Line Items]
Income from Operations	(111,941)	(100,484)	(90,306)
Depreciation, Depletion and Amortization, Nonproduction	$ 2,992	$ 4,951	$ 5,459