Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Feb. 11, 2018
Numerator:
Net income attributable to Cactus, Inc.	$ 26,807	$ 3,753
Denominator:
Weighted average Class A Shares Outstanding - basic	38,719,000	26,450,000
Effect of dilutive shares	36,527,000	198,000
Weighted average Class A Shares Outstanding - diluted	75,246,000	26,648,000
Earnings per Class A Share - basic	$ 0.69	$ 0.14
Earnings per Class A Share - diluted	$ 0.59	$ 0.14
Income attributable to noncontrolling interest, net of tax	$ 17,500
Corporate effective interest rate, if-converted method	24.00%
Effective tax rate	(2.00%)	5.90%
Class A Common Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Common Stock, Shares, Outstanding	46,390,804		37,654,000	0
Denominator:
Weighted average Class A Shares Outstanding - diluted	75,246,000	26,648,000
Earnings per Class A Share - basic	$ 0.69	$ 0.14
Earnings per Class A Share - diluted	$ 0.59	$ 0.14
Class B Common Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Common Stock, Shares, Outstanding	28,718,409		37,236,000	0
Denominator:
Effect of dilutive shares	36,292,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		48,440,000
Restricted Stock Units
Denominator:
Effect of dilutive shares	235,000