Segments - Revenue and Gross Margin by Reportable Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue and other financial information by reportable segment
Revenue	$ 781,461	$ 874,970	$ 965,485
Gross margin	422,544	497,777	509,247
Capital expenditures	97,885	140,302	385,198
Contract Operations
Revenue and other financial information by reportable segment
Revenue	648,311	738,918	771,539
Gross margin	403,825	477,831	474,279
Aftermarket Services
Revenue and other financial information by reportable segment
Revenue	133,150	136,052	193,946
Gross margin	18,719	19,946	34,968
Operating | Contract Operations
Revenue and other financial information by reportable segment
Capital expenditures	94,863	133,492	374,650
Operating | Aftermarket Services
Revenue and other financial information by reportable segment
Capital expenditures	2,675	5,308	8,714
Corporate
Revenue and other financial information by reportable segment
Capital expenditures	$ 347	$ 1,502	$ 1,834