Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Feb. 11, 2018
Numerator:
Net income attributable to Cactus Inc.				$ 34,759
Net income attributable to Cactus Inc.	$ 19,339	$ 18,672	$ 67,554
Net income attributable to non-controlling interest (1)			45,683
Net income attributable to Cactus Inc. - diluted (1)	$ 19,339	$ 18,672	$ 113,237	$ 34,759
Denominator:
Effect of dilutive shares (2)	227	408	31,077	340
Pre-tax income attributable to non-controlling interest			$ 60,100
Corporate effective interest rate, if-converted method			24.00%
Class A Common Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Common Stock, Shares, Outstanding	47,100		47,100		37,654	0
Denominator:
Weighted average Class A Shares Outstanding - basic	47,095	35,821	44,260	30,182
Weighted average Class A Shares Outstanding - diluted (2)	47,322	36,229	75,337	30,522
Earnings per Class A Share - basic	$ 0.41	$ 0.52	$ 1.53	$ 1.15
Earnings per Class A Share - diluted (1) (2)	$ 0.41	$ 0.52	$ 1.50	$ 1.14
Class B Common Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Common Stock, Shares, Outstanding	28,015		28,015		37,236	0
Denominator:
Effect of dilutive shares (2)			30,800
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	28,000	39,100		44,700
Restricted Stock Units
Denominator:
Effect of dilutive shares (2)			300