Business Segment Information (Summary Of Intercompany Segment Revenues) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Net revenues	$ 220,117	$ 217,110	$ 649,724	$ 644,413
Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues	(12,977)	(24,405)	(51,347)	(91,188)
Well Intervention [Member]
Segment Reporting Information [Line Items]
Net revenues	114,238	88,711	319,893	274,249
Well Intervention [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues	(4,784)	(5,797)	(15,052)	(18,231)
Robotics [Member]
Segment Reporting Information [Line Items]
Net revenues	90,370	95,107	242,940	238,762
Robotics [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues	(8,193)	(7,099)	(31,305)	(34,684)
Subsea Construction [Member]
Segment Reporting Information [Line Items]
Net revenues	4,120	37,673	69,305	162,581
Subsea Construction [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues			(317)	(3,720)
Production Facilities [Member]
Segment Reporting Information [Line Items]
Net revenues	24,366	20,024	68,933	60,009
Production Facilities [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues		(11,509)	(4,673)	(34,553)
Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues	$ (12,977)	$ (24,405)	$ (51,347)	$ (91,188)