Business Segment Information - Total Assets by Reportable Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total assets	$ 2,314,368	$ 2,399,959
Well Intervention [Member]
Segment Reporting Information [Line Items]
Total assets	1,475,066	1,484,109
Robotics [Member]
Segment Reporting Information [Line Items]
Total assets	240,393	274,926
Production Facilities [Member]
Segment Reporting Information [Line Items]
Total assets	158,999	182,007
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Total assets	$ 439,910	$ 458,917