Business Segment Information - Financial Data By Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Net revenues	$ 199,147	$ 201,728	$ 380,168	$ 368,551
Income (loss) from operations	14,194	23,072	(6,833)	23,341
Goodwill impairment	0	0	(6,689)	0
Reportable Segments
Segment Reporting Information [Line Items]
Income (loss) from operations	22,904	34,073	18,031	44,215
Intercompany Eliminations
Segment Reporting Information [Line Items]
Net revenues	(11,123)	(18,413)	(21,553)	(28,115)
Corporate, Eliminations and Other
Segment Reporting Information [Line Items]
Income (loss) from operations	(8,710)	(11,001)	(18,175)	(20,874)
Well Intervention
Segment Reporting Information [Line Items]
Net revenues	145,841	159,074	286,493	281,305
Goodwill impairment			(6,689)
Well Intervention | Reportable Segments
Segment Reporting Information [Line Items]
Net revenues	145,841	159,074	286,493	281,305
Income (loss) from operations	11,758	26,672	6,066	36,313
Well Intervention | Intercompany Eliminations
Segment Reporting Information [Line Items]
Net revenues	(3,910)	(9,812)	(7,214)	(13,037)
Robotics
Segment Reporting Information [Line Items]
Net revenues	50,836	45,446	86,094	84,487
Robotics | Reportable Segments
Segment Reporting Information [Line Items]
Net revenues	50,836	45,446	86,094	84,487
Income (loss) from operations	7,781	2,949	4,957	(955)
Robotics | Intercompany Eliminations
Segment Reporting Information [Line Items]
Net revenues	(7,213)	(8,601)	(14,339)	(15,078)
Production Facilities
Segment Reporting Information [Line Items]
Net revenues	13,593	15,621	29,134	30,874
Production Facilities | Reportable Segments
Segment Reporting Information [Line Items]
Net revenues	13,593	15,621	29,134	30,874
Income (loss) from operations	$ 3,365	$ 4,452	$ 7,008	$ 8,857