Business Segment Information (Intercompany Segment Assets) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Assets	$ 2,701,110	$ 2,544,280
Well Intervention [Member]
Segment Reporting Information [Line Items]
Assets	1,449,790	1,245,229
Robotics [Member]
Segment Reporting Information [Line Items]
Assets	324,231	282,373
Subsea Construction [Member]
Segment Reporting Information [Line Items]
Assets	33,402	38,054
Production Facilities [Member]
Segment Reporting Information [Line Items]
Assets	475,306	495,829
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Assets	$ 418,381	$ 482,795