Business Segment Information - Summary Of Intercompany Segment Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Net revenues	$ (150,329)	$ (107,267)	$ (254,857)	$ (198,306)
Intercompany Elimination [Member]
Segment Reporting Information [Line Items]
Net revenues	11,018	10,523	19,454	16,016
Intercompany Elimination [Member] | Well Intervention [Member]
Segment Reporting Information [Line Items]
Net revenues	2,895	2,201	4,268	2,842
Intercompany Elimination [Member] | Robotics [Member]
Segment Reporting Information [Line Items]
Net revenues	$ 8,123	$ 8,322	$ 15,186	$ 13,174