Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,721,005	$ 1,595,227	$ 728,974
Oil field services transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Oil field services transferred over time
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,721,005	$ 1,595,227	$ 728,974