Business Segment Information - Financial Data By Business Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Segment Reporting Information [Line Items]
Revenue	$ 672,545	$ 594,893	$ 545,838	$ 1,267,438	$ 1,016,258
Income from Operations	110,047	75,987	81,674	186,034	142,741
Oil And Gas [Member]
Segment Reporting Information [Line Items]
Revenue	604,693	532,184	489,398	1,136,877	906,963
Income from Operations	133,323	100,548	105,637	233,871	189,642
ROVs [Member]
Segment Reporting Information [Line Items]
Revenue	208,802	193,971	189,097	402,773	353,425
Income from Operations	64,168	56,933	58,145		105,551
Subsea Products [Member]
Segment Reporting Information [Line Items]
Revenue	191,783	172,081	195,800	363,864	353,118
Income from Operations	36,742	29,510	36,269	66,252	63,952
Subsea Projects [Member]
Segment Reporting Information [Line Items]
Revenue	90,448	72,676	34,733	163,124	72,302
Income from Operations	15,969	7,567	1,874	23,536	4,910
Asset Integrity [Member]
Segment Reporting Information [Line Items]
Revenue	113,660	93,456	69,768	207,116	128,118
Income from Operations	16,444	6,538	9,349	22,982	15,229
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Revenue	67,852	62,709	56,440	130,561	109,295
Income from Operations	6,645	3,509	3,160	10,154	5,677
Unallocated Expenses [Member]
Segment Reporting Information [Line Items]
Income from Operations	$ (29,921)	$ (28,070)	$ (27,123)	$ (57,991)	$ (52,578)