Business Segment Information - Summary Of Intercompany Segment Revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net revenues	$ 159,897	$ 193,490	$ 199,147	$ 181,021	$ 170,749	$ 212,609	$ 201,728	$ 166,823	$ 733,555	$ 751,909	$ 739,818
Well Intervention
Segment Reporting Information [Line Items]
Net revenues									539,249	593,300	560,568
Robotics
Segment Reporting Information [Line Items]
Net revenues									178,018	171,672	158,989
Intercompany Eliminations
Segment Reporting Information [Line Items]
Net revenues									(42,015)	(74,273)	(44,139)
Intercompany Eliminations | Well Intervention
Segment Reporting Information [Line Items]
Net revenues									(15,039)	(43,484)	(14,218)
Intercompany Eliminations | Well Intervention | Production Facilities
Segment Reporting Information [Line Items]
Net revenues										(27,500)
Intercompany Eliminations | Robotics
Segment Reporting Information [Line Items]
Net revenues									$ (26,976)	$ (30,789)	$ (29,921)