Business Segment Information - Financial Data By Business Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Segment Reporting Information [Line Items]
Revenue	$ 594,893	$ 574,197	$ 470,420
Income from Operations	75,987	82,468	61,067
Oil And Gas [Member]
Segment Reporting Information [Line Items]
Revenue	532,184	509,757	417,565
Income from Operations	100,548	109,085	84,005
ROVs [Member]
Segment Reporting Information [Line Items]
Revenue	193,971	200,681	164,328
Income from Operations	56,933	59,100	47,406
Subsea Products [Member]
Segment Reporting Information [Line Items]
Revenue	172,081	196,987	157,318
Income from Operations	29,510	36,743	27,683
Subsea Projects [Member]
Segment Reporting Information [Line Items]
Revenue	72,676	45,263	37,569
Income from Operations	7,567	6,769	3,036
Asset Integrity [Member]
Segment Reporting Information [Line Items]
Revenue	93,456	66,826	58,350
Income from Operations	6,538	6,473	5,880
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Revenue	62,709	64,440	52,855
Income from Operations	3,509	5,215	2,517
Unallocated Expenses [Member]
Segment Reporting Information [Line Items]
Income from Operations	$ (28,070)	$ (31,832)	$ (25,455)