Equity - Redemptions and Dividends (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions			3 Months Ended		12 Months Ended	14 Months Ended
	Mar. 19, 2020	Jan. 30, 2020	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Mar. 31, 2019
Equity
Dividends declared per common share			$ 0.09
CACTUS INC
Equity
Cash distributions to unit holders			$ 3.7
CW Unit Holders other than Cactus, Inc.
Equity
Cash distributions to unit holders	$ 2.2			$ 0.2
Cactus LLC
Equity
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest			62.90%		62.80%
March 2019 Secondary Offering
Equity
Offering expenses				$ 1.0		$ 1.0
Class A Common Stock
Equity
Common Stock, Shares, Outstanding			47,398		47,159
Shares Outstanding Per Class As Percent Of Total			62.90%
Common stock, par value			$ 0.01		$ 0.01
Dividends declared per common share		$ 0.09
Dividend paid	$ 4.3
Class A Common Stock | CW Units Redeemed For Class A Common Stock [Member]
Equity
CW Unit redemptions				8,500		32,600
Class B Common Stock
Equity
Common Stock, Shares, Outstanding			27,958		27,958
Shares Outstanding Per Class As Percent Of Total			37.10%
Common stock, par value			$ 0.01		$ 0.01