Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net income attributable to Cactus Inc.	$ 6,233	$ 19,339	$ 31,244	$ 67,554
Net income attributable to non-controlling interest	3,522	0	17,271	45,683
Net income attributable to Cactus Inc. - diluted	$ 9,755	$ 19,339	$ 48,515	$ 113,237
Denominator:
Effect of dilutive shares (in shares)	28,112	227	28,021	31,077
Weighted average Class A shares outstanding - diluted (in shares)	75,622	47,322	75,427	75,337
Earnings per Class A share - basic (in dollars per share)	$ 0.13	$ 0.41	$ 0.66	$ 1.53
Earnings per Class A share - diluted (in dollars per share)	$ 0.13	$ 0.41	$ 0.64	$ 1.50
Corporate effective interest rate, if-converted method	25.50%		25.50%	24.00%
Class A Common Stock
Denominator:
Weighted average Class A Shares Outstanding - basic (in shares)	47,510	47,095	47,406	44,260
Weighted average Class A shares outstanding - diluted (in shares)	75,622	47,322	75,427	75,337
Earnings per Class A share - basic (in dollars per share)	$ 0.13	$ 0.41	$ 0.66	$ 1.53
Earnings per Class A share - diluted (in dollars per share)	$ 0.13	$ 0.41	$ 0.64	$ 1.50
Class B Common Stock
Denominator:
Effect of dilutive shares (in shares)	28,100		28,000	31,100
Antidilutive securities excluded from computation of earnings per share (in shares)		28,000