Business Segment Information - Financial Data by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Net revenues	$ 161,245	$ 182,462	$ 359,551	$ 538,119
Income (loss) from operations	21,470	18,372	(18,581)	48,374
Reportable Segments [Member] | Well Intervention [Member]
Segment Reporting Information [Line Items]
Net revenues	108,287	94,895	214,262	284,621
Income (loss) from operations	24,413	6,233	7,187	25,162
Reportable Segments [Member] | Robotics [Member]
Segment Reporting Information [Line Items]
Net revenues	48,897	83,310	119,805	238,582
Income (loss) from operations	(94)	14,329	(21,667)	28,089
Reportable Segments [Member] | Production Facilities [Member]
Segment Reporting Information [Line Items]
Net revenues	17,128	19,133	54,567	57,811
Income (loss) from operations	8,312	6,938	25,225	19,960
Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues	(13,067)	(14,876)	(29,083)	(42,895)
Income (loss) from operations	(873)	(163)	(542)	(256)
Intercompany Elimination [Member] | Well Intervention [Member]
Segment Reporting Information [Line Items]
Net revenues	(2,898)	(7,324)	(5,740)	(18,687)
Intercompany Elimination [Member] | Robotics [Member]
Segment Reporting Information [Line Items]
Net revenues	(10,169)	(7,552)	(23,343)	(24,208)
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	$ (10,288)	$ (8,965)	$ (28,784)	$ (24,581)