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Organization and Nature of Operations - Follow-on Offering (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended	9 Months Ended
	Jul. 16, 2018	Feb. 14, 2018	Feb. 12, 2018	Sep. 30, 2018	Sep. 30, 2018	Feb. 11, 2018
Follow-on Offering
Deferred tax asset, net	$ 116,200		$ 74,100	$ 179,265	$ 179,265
Liability related to tax receivable agreement	$ 98,800		$ 63,000	$ 161,797	161,797
Tax savings payable to TRA Holders (as a percent)	85.00%		85.00%
Additional paid-in capital related to tax receivable agreement	$ 17,400		$ 11,100		$ 28,552
Equity reclassified to Cactus Inc from non-controlling interest representing the additional CW units acquired	$ 25,200
Common stock, shares outstanding	74,889,772
Members' Equity (Deficit) \| Cactus LLC
Follow-on Offering
Redeem CW Units from certain direct and indirect owners (in units)			8,667,841
Follow-on Offering
Follow-on Offering
Offering expenses	$ 700
Class A Common Stock
Follow-on Offering
Common stock, shares outstanding	37,646,562			37,646,562	37,646,562	0
Voting power of shares outstanding as a percent of the total shares outstanding				50.30%
Class A Common Stock \| Follow-on Offering
Follow-on Offering
Number of shares issued	11,196,562
Share price (in dollars per share)	$ 33.25
Net proceeds from issuance of Class A common shares	$ 359,300
Class A Common Stock \| Base Shares
Follow-on Offering
Number of shares issued	10,000,000
Class A Common Stock \| Underwriter's option
Follow-on Offering
Number of shares issued	1,196,562	3,450,000
Class B Common Stock
Follow-on Offering
Number of shares issued			51,889,772
Redeem CW Units from certain direct and indirect owners (in units)	11,196,562
Common stock, shares outstanding	37,243,210			37,243,210	37,243,210	0
Voting power of shares outstanding as a percent of the total shares outstanding				49.70%
Class B Common Stock \| Cactus LLC
Follow-on Offering
Redeem CW Units from certain direct and indirect owners (in units)		3,450,000
Class B Common Stock \| Follow-on Offering
Follow-on Offering
Cancelation of common stock in conjunction with follow-on offering	$ 100