Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income attributable to Cactus Inc.	$ 18,058	$ 19,339	$ 21,408	$ 26,807	$ 16,924	$ 18,672	$ 12,334	$ 3,753	$ 85,612	$ 51,683
Net income attributable to non-controlling interest (1)									56,012
Net income attributable to Cactus Inc. - diluted (1)									$ 141,624	$ 51,683
Denominator:
Effect of dilutive shares (2)									30,370	366
Earnings per Class A share - basic					$ 0.45	$ 0.52	$ 0.47	$ 0.14		$ 1.60
Earnings per Class A Share - diluted (1) (2)	$ 0.38	$ 0.41	$ 0.45	$ 0.59	$ 0.44	$ 0.52	$ 0.46	$ 0.14	$ 1.88	$ 1.58
Pre-tax income attributable to non-controlling interest									$ 73,700
Corporate effective interest rate, if-converted method									24.00%
Class A Common Stock
Denominator:
Weighted average Class A Shares Outstanding - basic									44,983	32,329
Weighted average Class A Shares Outstanding - diluted (2)									75,353	32,695
Earnings per Class A share - basic	$ 0.38	$ 0.41	$ 0.46	$ 0.69					$ 1.90	$ 1.60
Earnings per Class A Share - diluted (1) (2)									$ 1.88	$ 1.58
Class B Common Stock
Denominator:
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount										37,200