| Cover | Jun. 16, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jun. 16, 2021 |
| Entity File Number | 001-38390 |
| Entity Registrant Name | Cactus, Inc. |
| Entity Central Index Key | 0001699136 |
| Entity Tax Identification Number | 35-2586106 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 920 Memorial City Way, 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A Common Stock, par value $0.01 |
| Trading Symbol | WHD |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
