Revenue From Contracts With Customers - Disaggregation Of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Net revenues	$ 199,147	$ 201,728	$ 380,168	$ 368,551
Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues	(11,123)	(18,413)	(21,553)	(28,115)
Well Intervention
Disaggregation of Revenue [Line Items]
Net revenues	145,841	159,074	286,493	281,305
Well Intervention | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues	(3,910)	(9,812)	(7,214)	(13,037)
Robotics
Disaggregation of Revenue [Line Items]
Net revenues	50,836	45,446	86,094	84,487
Robotics | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues	(7,213)	(8,601)	(14,339)	(15,078)
Production Facilities
Disaggregation of Revenue [Line Items]
Net revenues	13,593	15,621	29,134	30,874
Short-term
Disaggregation of Revenue [Line Items]
Net revenues	91,452	91,489	196,217	146,224
Short-term | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues	0	0	0	0
Short-term | Well Intervention
Disaggregation of Revenue [Line Items]
Net revenues	55,368	62,788	137,692	92,593
Short-term | Robotics
Disaggregation of Revenue [Line Items]
Net revenues	36,084	28,701	58,525	53,631
Short-term | Production Facilities
Disaggregation of Revenue [Line Items]
Net revenues	0	0	0	0
Long-term
Disaggregation of Revenue [Line Items]
Net revenues	107,695	110,239	183,951	222,327
Long-term | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues	(11,123)	(18,413)	(21,553)	(28,115)
Long-term | Well Intervention
Disaggregation of Revenue [Line Items]
Net revenues	90,473	96,286	148,801	188,712
Long-term | Robotics
Disaggregation of Revenue [Line Items]
Net revenues	14,752	16,745	27,569	30,856
Long-term | Production Facilities
Disaggregation of Revenue [Line Items]
Net revenues	$ 13,593	$ 15,621	$ 29,134	$ 30,874