Business Segment Information - Financial Data By Business Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Segment Reporting Information [Line Items]
Revenue	$ 786,772	$ 918,927	$ 840,201
Income from Operations	106,650	152,239	132,862
Oil And Gas [Member]
Segment Reporting Information [Line Items]
Revenue	712,241	848,021	778,178
Income from Operations	139,497	183,430	165,878
ROVs [Member]
Segment Reporting Information [Line Items]
Revenue	219,447	259,544	255,819
Income from Operations	62,182	79,635	76,740
Subsea Products [Member]
Segment Reporting Information [Line Items]
Revenue	240,729	314,739	260,010
Income from Operations	50,014	63,796	54,516
Subsea Projects [Member]
Segment Reporting Information [Line Items]
Revenue	153,572	162,623	138,190
Income from Operations	22,276	34,113	20,537
Asset Integrity [Member]
Segment Reporting Information [Line Items]
Revenue	98,493	111,115	124,159
Income from Operations	5,025	5,886	14,085
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Revenue	74,531	70,906	62,023
Income from Operations	5,020	7,214	2,955
Unallocated Expenses [Member]
Segment Reporting Information [Line Items]
Income from Operations	$ (37,867)	$ (38,405)	$ (35,971)