Revenue From Contracts With Customers - Schedule Of Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Net revenues	$ 158,356	$ 212,575	$ 204,625	$ 164,262	$ 163,266	$ 163,260	$ 150,329	$ 104,528	$ 739,818	$ 581,383	$ 487,582
Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues									(44,139)	(42,065)	(39,356)
Well Intervention
Disaggregation of Revenue [Line Items]
Net revenues									560,568
Well Intervention | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues									(14,218)	(11,489)	(8,442)
Robotics
Disaggregation of Revenue [Line Items]
Net revenues									158,989
Robotics | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues									(29,921)	$ (30,576)	$ (30,914)
Production Facilities
Disaggregation of Revenue [Line Items]
Net revenues									64,400
Short-term
Disaggregation of Revenue [Line Items]
Net revenues									288,366
Short-term | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues									0
Short-term | Well Intervention
Disaggregation of Revenue [Line Items]
Net revenues									199,294
Short-term | Robotics
Disaggregation of Revenue [Line Items]
Net revenues									89,072
Short-term | Production Facilities
Disaggregation of Revenue [Line Items]
Net revenues									0
Long-term
Disaggregation of Revenue [Line Items]
Net revenues									451,452
Long-term | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues									(44,139)
Long-term | Well Intervention
Disaggregation of Revenue [Line Items]
Net revenues									361,274
Long-term | Robotics
Disaggregation of Revenue [Line Items]
Net revenues									69,917
Long-term | Production Facilities
Disaggregation of Revenue [Line Items]
Net revenues									$ 64,400