Business Segment Information (Summary Of Financial Data By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 253,572		$ 197,429
Income (loss) from operations	66,948		15,238
Equity in earnings of investments	708		610
Gain on sale of assets	11,496
Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Revenues	(17,516)		(21,018)
Income (loss) from operations	(1,198)		(1,720)
Well Intervention [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	159,700		106,332
Income (loss) from operations	48,733		36,450
Well Intervention [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Revenues	(5,461)		(3,829)
Robotics [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	87,890		64,196
Income (loss) from operations	11,219		(697)
Robotics [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Revenues	(12,055)		(12,199)
Subsea Construction [Member]
Segment Reporting Information [Line Items]
Gain on sale of assets	10,500
Subsea Construction [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	358		27,526
Income (loss) from operations	10,685	[1]	3,551	[1]
Subsea Construction [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Revenues			(317)
Production Facilities [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	23,140		20,393
Income (loss) from operations	11,384		11,185
Production Facilities [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Revenues			(4,673)
Corporate and Other [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	$ (13,875)		$ (33,531)

[1] Amount in 2014 includes the $10.5 million gain on the sale in January 2014 of our Ingleside spoolbase.