Business Segment Information - Financial Data By Business Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Revenue	$ 820,372	$ 718,552	$ 672,545	$ 1,538,924	$ 1,267,438
Income from Operations	146,337	108,290	110,047	254,627	186,034
Oil And Gas [Member]
Segment Reporting Information [Line Items]
Revenue	743,114	646,937	604,693	1,390,051	1,136,877
Income from Operations	171,908	132,573	133,323	304,481	233,871
ROVs [Member]
Segment Reporting Information [Line Items]
Revenue	242,163	229,628	208,802	471,791	402,773
Income from Operations	69,219	65,835	64,168	135,054	121,101
Subsea Products [Member]
Segment Reporting Information [Line Items]
Revenue	258,016	214,005	191,783	472,021	363,864
Income from Operations	62,060	42,779	36,742	104,839	66,252
Subsea Projects [Member]
Segment Reporting Information [Line Items]
Revenue	118,195	88,455	90,448	206,650	163,124
Income from Operations	23,990	11,620	15,969	35,610	23,536
Asset Integrity [Member]
Segment Reporting Information [Line Items]
Revenue	124,740	114,849	113,660	239,589	207,116
Income from Operations	16,639	12,339	16,444	28,978	22,982
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Revenue	77,258	71,615	67,852	148,873	130,561
Income from Operations	10,165	8,676	6,645	18,841	10,154
Unallocated Expenses [Member]
Segment Reporting Information [Line Items]
Income from Operations	$ (35,736)	$ (32,959)	$ (29,921)	$ (68,695)	$ (57,991)