Business Segment Information - Total Assets By Reportable Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total assets	$ 2,484,669	$ 2,596,731
Corporate and Other
Segment Reporting Information [Line Items]
Total assets	83,764	122,449
Well Intervention | Reportable Segments
Segment Reporting Information [Line Items]
Total assets	2,128,563	2,180,180
Robotics | Reportable Segments
Segment Reporting Information [Line Items]
Total assets	136,868	151,478
Production Facilities | Reportable Segments
Segment Reporting Information [Line Items]
Total assets	$ 135,474	$ 142,624