Revenue From Contracts With Customers - Disaggregation Of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Net revenues	$ 193,490	$ 212,609	$ 573,658	$ 581,160
Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues	(11,282)	(23,283)	(32,835)	(51,398)
Well Intervention
Disaggregation of Revenue [Line Items]
Net revenues	140,803	170,206	427,296	451,511
Well Intervention | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues	(4,120)	(15,318)	(11,334)	(28,355)
Robotics
Disaggregation of Revenue [Line Items]
Net revenues	49,802	51,909	135,896	136,396
Robotics | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues	(7,162)	(7,965)	(21,501)	(23,043)
Production Facilities
Disaggregation of Revenue [Line Items]
Net revenues	14,167	13,777	43,301	44,651
Short-term
Disaggregation of Revenue [Line Items]
Net revenues	75,689	79,827	271,906	226,051
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	46,907	53,018	184,599	145,611
Short-term | Robotics
Disaggregation of Revenue [Line Items]
Net revenues	28,782	26,809	87,307	80,440
Short-term | Production Facilities
Disaggregation of Revenue [Line Items]
Net revenues	0	0	0	0
Long-term
Disaggregation of Revenue [Line Items]
Net revenues	117,801	132,782	301,752	355,109
Long-term | Intercompany Eliminations
Disaggregation of Revenue [Line Items]
Net revenues	(11,282)	(23,283)	(32,835)	(51,398)
Long-term | Well Intervention
Disaggregation of Revenue [Line Items]
Net revenues	93,896	117,188	242,697	305,900
Long-term | Robotics
Disaggregation of Revenue [Line Items]
Net revenues	21,020	25,100	48,589	55,956
Long-term | Production Facilities
Disaggregation of Revenue [Line Items]
Net revenues	$ 14,167	$ 13,777	$ 43,301	$ 44,651