Business Segment Information (Summary Of Intercompany Segment Revenues) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Net revenues	$ (207,160)	$ (340,837)	$ (305,587)	$ (253,572)	$ (226,837)	$ (220,117)	$ (232,178)	$ (197,429)	$ (1,107,156)	$ (876,561)	$ (846,109)
Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues									74,450	68,607	133,775
Well Intervention [Member]
Segment Reporting Information [Line Items]
Net revenues									(667,849)	(452,452)	(378,546)
Well Intervention [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues									29,875	22,448	36,781
Robotics [Member]
Segment Reporting Information [Line Items]
Net revenues									(420,224)	(333,246)	(328,726)
Robotics [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues									44,575	41,169	46,465
Production Facilities [Member]
Segment Reporting Information [Line Items]
Net revenues									(93,175)	(88,149)	(80,091)
Production Facilities [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues										4,673	46,057
Subsea Construction [Member]
Segment Reporting Information [Line Items]
Net revenues									(358)	(71,321)	(192,521)
Subsea Construction [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues										317	4,472
Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues									$ 74,450	$ 68,607	$ 133,775