Business Segment Information (Summary Of Financial Data By Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net revenues	$ 166,016	$ 305,587	$ 355,657	$ 559,159
Income (loss) from operations	7,674	78,756	30,002	145,704
Equity in earnings (losses) of investments	(323)	(507)	(302)	201
Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues	(15,053)	(19,384)	(28,019)	(36,900)
Income (loss) from operations	(199)	45	(93)	(1,153)
Well Intervention [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net revenues	85,675	181,218	189,726	340,918
Income (loss) from operations	4,135	64,775	18,929	113,508
Well Intervention [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues	(6,417)	(7,956)	(11,363)	(13,417)
Robotics [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net revenues	75,101	119,704	155,272	207,594
Income (loss) from operations	4,303	20,799	13,760	32,018
Robotics [Member] | Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues	(8,636)	(11,428)	(16,656)	(23,483)
Production Facilities [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net revenues	20,293	24,049	38,678	47,189
Income (loss) from operations	8,444	10,459	13,022	21,843
Other [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net revenues	0	0	0	358
Corporate and Other [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	$ (9,009)	$ (17,322)	$ (15,616)	$ (20,512)