Business Segment Information - Financial Data By Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Net revenues	$ 193,490	$ 212,609	$ 573,658	$ 581,160
Income from operations	19,015	38,998	12,182	62,339
Goodwill impairment	0	0	(6,689)	0
Reportable Segments
Segment Reporting Information [Line Items]
Income from operations	29,961	49,615	47,992	93,830
Intercompany Eliminations
Segment Reporting Information [Line Items]
Net revenues	(11,282)	(23,283)	(32,835)	(51,398)
Corporate, Eliminations and Other
Segment Reporting Information [Line Items]
Income from operations	(10,946)	(10,617)	(29,121)	(31,491)
Well Intervention
Segment Reporting Information [Line Items]
Net revenues	140,803	170,206	427,296	451,511
Goodwill impairment			(6,689)
Well Intervention | Reportable Segments
Segment Reporting Information [Line Items]
Net revenues	140,803	170,206	427,296	451,511
Income from operations	18,844	37,689	24,910	74,002
Well Intervention | Intercompany Eliminations
Segment Reporting Information [Line Items]
Net revenues	(4,120)	(15,318)	(11,334)	(28,355)
Robotics
Segment Reporting Information [Line Items]
Net revenues	49,802	51,909	135,896	136,396
Robotics | Reportable Segments
Segment Reporting Information [Line Items]
Net revenues	49,802	51,909	135,896	136,396
Income from operations	6,983	8,876	11,940	7,921
Robotics | Intercompany Eliminations
Segment Reporting Information [Line Items]
Net revenues	(7,162)	(7,965)	(21,501)	(23,043)
Production Facilities
Segment Reporting Information [Line Items]
Net revenues	14,167	13,777	43,301	44,651
Production Facilities | Reportable Segments
Segment Reporting Information [Line Items]
Net revenues	14,167	13,777	43,301	44,651
Income from operations	$ 4,134	$ 3,050	$ 11,142	$ 11,907