Preparation of Interim Financial Statements and Other Items - Effective Income Tax (Details)1 - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Effective income tax rate reconciliation
Statutory tax rate (as a percent)			21.00%
Income taxes at 21% statutory tax rate	$ 9,710		$ 15,603
Profit of Cactus LL Pre-IPO not subject to U.S. federal tax			(2,808)
Profit of non-controlling interest not subject to U.S. federal tax	(6,280)		(8,206)
Foreign earnings subject to different tax rates	126		176
State income taxes	698		1,016
Foreign withholding taxes	223		296
Change in valuation allowance	18		(2)
Other	202		274
Total provision for income taxes	$ 4,697	$ 309	$ 6,349	$ 463