Organization and Nature of Operations - Follow-on Offering (Details) - USD ($) $ / shares in Units, $ in Millions				12 Months Ended
	Jul. 16, 2018	Feb. 14, 2018	Feb. 12, 2018	Dec. 31, 2018	Feb. 11, 2018
Follow-on Offering
CW units acquired in exchange for net proceeds from public offering	11,196,562
Redemption CW Units (in units)				7,068
Weighted average price per unit redeemed				$ 31.30
Tax savings payable to TRA Holders (as a percent)	85.00%		85.00%	85.00%
Portion of net cash savings per tax agreement retained by entity	15.00%		15.00%	15.00%
Equity reclassified to Cactus Inc from non-controlling interest representing the additional CW units acquired	$ 25.2
Common stock, shares outstanding				74,889,772
Cactus LLC
Follow-on Offering
Redemption CW Units (in units)	11,196,562
Members' Equity (Deficit) | Cactus LLC
Follow-on Offering
Redemption CW Units (in units)			8,667,841
Follow-on Offering
Follow-on Offering
Proceeds from the sale of common stock	$ 359.3
Offering expenses	$ 0.7
Underwriter's option
Follow-on Offering
Number of shares canceled		3,450,000
Class A Common Stock
Follow-on Offering
Increase (decrease) in shares outstanding due to redemption of CW units				7,068
Common stock, shares outstanding				37,653,630	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
Price per share	$ 33.25
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
Cancelation of common stock in conjunction with follow-on offering	$ 0.1
Increase (decrease) in shares outstanding due to redemption of CW units				(7,068)
Common stock, shares outstanding				37,236,142	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
Redemption CW Units (in units)		3,450,000