Commitments and Contingencies (Details) $ in Millions				3 Months Ended		6 Months Ended		25 Months Ended
Commitments and Contingencies (Details) $ in Millions	Sep. 11, 2025 claim	Dec. 23, 2024 lawsuit EUR (€)	Feb. 15, 2023 officer_and_director plaintiff	Oct. 31, 2025 USD ($)	Oct. 31, 2024 USD ($)	Oct. 31, 2025 USD ($)	Oct. 31, 2024 USD ($)	Jun. 28, 2024 claim	Jul. 31, 2024 phase	Feb. 27, 2024 EUR (€)	Jan. 31, 2024 phase	Jul. 31, 2023 phase	Apr. 30, 2023 phase	Oct. 31, 2022 phase	Jan. 31, 2022 phase	Aug. 25, 2021 ft²
Long-term Purchase Commitment [Line Items]
Purchase commitment, incurred cost				$ 21.6	$ 25.6	$ 60.6	$ 44.8
Lease, area under lease \| ft²																283,015
Lease, number of phases \| phase									7		6	5	4	3	2
The Reckstin Family Trust v. C3.ai, Inc. \| Settled Litigation
Long-term Purchase Commitment [Line Items]
Number of additional plaintiffs \| plaintiff			3
Number of current and former officers and directors \| officer_and_director			4
Suri V. Siebel Et Al., Rabasca V. Siebel Et Al., Vo V. Siebel Et Al., Lanfair V. Siebel Et Al., Pankow V. Seibel Et Al., Rosenfeld V. Siebel Et Al. \| Pending Litigation
Long-term Purchase Commitment [Line Items]
Number of actions filed \| claim								6
Jaffee v. Siebel et al., Joshua Steffens V. C3.ai, Inc. Et Al., And Fernicola v. Siebel et al. \| Pending Litigation
Long-term Purchase Commitment [Line Items]
Number of actions filed \| claim	3
Enel Global Services S.R.L And Any Involved Corporate Affiliates ("Enel") \| Pending Litigation
Long-term Purchase Commitment [Line Items]
Number of actions filed \| lawsuit		2
Unrecorded amount \| €										€ 2,100,000,000
Loss contingency, patents allegedly infringed, number \| €		2
Cloud Hosting Services
Long-term Purchase Commitment [Line Items]
Remaining contractual commitment				402.1		402.1
Professional services
Long-term Purchase Commitment [Line Items]
Remaining contractual commitment				$ 83.2		$ 83.2
Professional services \| Minimum
Long-term Purchase Commitment [Line Items]
Purchase commitment, term						1 year
Professional services \| Maximum
Long-term Purchase Commitment [Line Items]
Purchase commitment, term						5 years

C3.ai, Inc. 10-Q