Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2021	Feb. 24, 2022	Jun. 30, 2021
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2021
Document Transition Report	false
Entity File Number	001-38390
Entity Registrant Name	Cactus, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	35-2586106
Entity Address, Address Line One	920 Memorial City Way
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77024
City Area Code	713
Local Phone Number	626-8800
Title of 12(b) Security	Class A Common Stock, par value $0.01
Trading Symbol	WHD
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 2.1
Documents Incorporated by Reference	None.
Entity Central Index Key	0001699136
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false
Class A Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		59,035,237
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		16,674,282