Business Segment Information - Financial Data By Business Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Revenue	$ 973,089	$ 927,407	$ 853,297	$ 2,740,697	$ 2,392,221
Income from Operations	181,918	161,311	153,736	476,091	408,363
Oil And Gas [Member]
Segment Reporting Information [Line Items]
Revenue	908,424	861,954	780,439	2,548,556	2,170,490
Income from Operations	218,702	197,100	183,520	581,680	488,001
ROVs [Member]
Segment Reporting Information [Line Items]
Revenue	285,385	268,274	254,979	809,478	726,770
Income from Operations	88,350	75,825	74,710	240,915	209,764
Subsea Products [Member]
Segment Reporting Information [Line Items]
Revenue	336,745	327,252	263,671	924,007	735,692
Income from Operations	83,430	79,497	61,737	217,443	166,576
Subsea Projects [Member]
Segment Reporting Information [Line Items]
Revenue	151,560	136,199	143,132	425,949	349,782
Income from Operations	27,339	25,863	30,700	73,739	66,310
Asset Integrity [Member]
Segment Reporting Information [Line Items]
Revenue	134,734	130,229	118,657	389,122	358,246
Income from Operations	19,583	15,915	16,373	49,583	45,351
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Revenue	64,665	65,453	72,858	192,141	221,731
Income from Operations	2,863	198	6,400	6,016	25,241
Unallocated Expenses [Member]
Segment Reporting Information [Line Items]
Income from Operations	$ (39,647)	$ (35,987)	$ (36,184)	$ (111,605)	$ (104,879)