Business Segment Information - Summary Of Intercompany Segment Revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net revenues	$ 170,749	$ 212,609	$ 201,728	$ 166,823	$ 158,356	$ 212,575	$ 204,625	$ 164,262	$ 751,909	$ 739,818	$ 581,383
Well Intervention
Segment Reporting Information [Line Items]
Net revenues									593,300	560,568
Robotics
Segment Reporting Information [Line Items]
Net revenues									171,672	158,989
Intercompany Eliminations
Segment Reporting Information [Line Items]
Net revenues									(74,273)	(44,139)	(42,065)
Intercompany Eliminations | Well Intervention
Segment Reporting Information [Line Items]
Net revenues									(43,484)	(14,218)	(11,489)
Intercompany Eliminations | Well Intervention | Droshky Prospect
Segment Reporting Information [Line Items]
Net revenues									(27,500)
Intercompany Eliminations | Robotics
Segment Reporting Information [Line Items]
Net revenues									$ (30,789)	$ (29,921)	$ (30,576)