| Document and Entity Information | Dec. 17, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Dec. 17, 2021 |
| Entity Registrant Name | C3.AI, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-39744 |
| Entity Tax Identification Number | 26-3999357 |
| Entity Address, Address Line One | 1300 Seaport Blvd, |
| Entity Address, Address Line Two | Suite 500 |
| Entity Address, City or Town | Redwood City, |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94063 |
| City Area Code | 650 |
| Local Phone Number | 503-2200 |
| 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 $0.001 per share |
| Trading Symbol | AI |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001577526 |
| Amendment Flag | false |
