Preparation of Interim Financial Statements and Other Items - Effective Income Tax (Details)1 - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Effective income tax rate:
Income taxes at 21% statutory tax rate	$ 5,893
Statutory tax rate	21.00%
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	(1,926)
Foreign earnings subject to different tax rates	50
State income taxes	318
Foreign withholding taxes	73
Change in valuation allowance	(20)
Other	72
Total provision for income taxes	$ 1,652	$ 154