Organization and Nature of Operations - Reorganization and Other IPO Related (Details) $ / shares in Units, $ in Thousands					9 Months Ended
	Jul. 16, 2018 USD ($) shares	Feb. 14, 2018 shares	Feb. 12, 2018 USD ($) Vote item $ / shares shares	Jan. 25, 2018 USD ($)	Sep. 30, 2018 USD ($) $ / shares
Reorganization and Other IPO related items
Number of shares canceled | shares		3,450,000
Write off of stock issuance costs against equity | $			$ 2,200
Write-off of unamortized debt discount and deferred loan costs | $			$ 4,300		$ 4,305
Restricted stock unit awards issued (in shares) | shares			737,493
Deferred tax asset, net | $	$ 116,200		$ 74,100		179,265
Liability related to tax receivable agreement | $	$ 98,800		$ 63,000		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
Retained earnings | $					34,759
Non-controlling interest | $			130,900
Member distributions prior to IPO | $				$ 26,000	26,000
Cactus LLC
Reorganization and Other IPO related items
Retained earnings | $			$ 0
Members' Equity (Deficit)
Reorganization and Other IPO related items
Member distributions prior to IPO | $					$ 26,000
Members' Equity (Deficit) | Cactus LLC
Reorganization and Other IPO related items
Redeem CW Units from certain direct and indirect owners (in units) | shares			8,667,841
Underwriter's option | Members' Equity (Deficit)
Reorganization and Other IPO related items
Number of CW Units acquired with the proceeds from the sale of common stock | shares		3,450,000
IPO | Members' Equity (Deficit)
Reorganization and Other IPO related items
Number of CW Units acquired with the proceeds from the sale of common stock | shares			23,000,000
Class A Common Stock
Reorganization and Other IPO related items
Common stock, par value | $ / shares					$ 0.01
Class A Common Stock | Underwriter's option
Reorganization and Other IPO related items
Number of shares issued | shares	1,196,562	3,450,000
Class A Common Stock | Follow-on Offering
Reorganization and Other IPO related items
Number of shares issued | shares	11,196,562
Class A Common Stock | IPO
Reorganization and Other IPO related items
Number of shares issued | shares			23,000,000
Common stock, par value | $ / shares			$ 0.01
Class B Common Stock
Reorganization and Other IPO related items
Redeem CW Units from certain direct and indirect owners (in units) | shares	11,196,562
Number of shares issued | shares			51,889,772
Common stock, par value | $ / shares			$ 0.01		$ 0.01
Economic interest of shares | $			$ 0
Number of votes per holder | Vote			1
Class B Common Stock | Cactus LLC
Reorganization and Other IPO related items
Redeem CW Units from certain direct and indirect owners (in units) | shares		3,450,000
Class B Common Stock | Members' Equity (Deficit) | Cactus LLC
Reorganization and Other IPO related items
Number of common stock for each unit | item			1