Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 30, 2019
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Entity Registrant Name	Cactus, Inc.
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Central Index Key	0001699136
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A Common Stock
Entity Common Stock, Shares Outstanding		47,101,875
Class B Common Stock
Entity Common Stock, Shares Outstanding		28,014,923