Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 07, 2019
Entity Registrant Name	Cactus, Inc.
Entity Central Index Key	0001699136
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Trading Symbol	WHD
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Class A Common Stock
Entity Common Stock, Shares Outstanding		46,780,909
Class B Common Stock
Entity Common Stock, Shares Outstanding		28,329,012