Business Segment Information - Total Assets By Reportable Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total assets	$ 2,421,749	$ 2,498,278
Corporate, Eliminations and Other
Segment Reporting Information [Line Items]
Total assets	96,747	101,874
Well Intervention | Reportable Segments
Segment Reporting Information [Line Items]
Total assets	2,081,641	2,134,081
Robotics | Reportable Segments
Segment Reporting Information [Line Items]
Total assets	108,372	132,550
Production Facilities | Reportable Segments
Segment Reporting Information [Line Items]
Total assets	$ 134,989	$ 129,773