Commitments and Contingencies (Details)		1 Months Ended			3 Months Ended
	Aug. 25, 2021 USD ($) ft² phase	Jul. 31, 2022 USD ($)	Feb. 29, 2020	Nov. 30, 2019 USD ($)	Jul. 31, 2022 USD ($)	Jul. 31, 2021 USD ($)	Apr. 30, 2022 USD ($)
Long-term Purchase Commitment [Line Items]
Lease, area under lease | ft²	283,015
Lease, total undiscounted base rent payments over term of lease	$ 103,100,000
Lease, term of rent abatement per phase, following rent commencement date	6 months
Lease, monthly base rent	$ 500,000
Lessee, tenant improvement allowance	$ 44,200,000
Lease, term	126 months
Lease, period after date phase one delivered	9 months
Lease, number of phases | phase	2
Operating lease, liability		$ 26,500,000			$ 26,500,000
Operating lease, right-of-use assets		26,500,000			26,500,000
Landlord | Letter of Credit | Line of Credit
Long-term Purchase Commitment [Line Items]
Letter of credit outstanding	$ 12,600,000
Maximum
Long-term Purchase Commitment [Line Items]
Lease, monthly base rent	$ 1,000,000
C3.ai DTI Grants Program
Long-term Purchase Commitment [Line Items]
Grants, payment period			5 years
Grants, potential remaining contributions		31,600,000			31,600,000		$ 31,600,000
Web-Hosting Services, November 2019-November 2022
Long-term Purchase Commitment [Line Items]
Purchase commitment				$ 30,000,000
Purchase commitment, term				3 years
Purchase commitment, incurred cost					4,100,000	$ 3,200,000
Web-Hosting Services, November 2020
Long-term Purchase Commitment [Line Items]
Purchase commitment				$ 10,000,000
Web-Hosting Services, November 2021
Long-term Purchase Commitment [Line Items]
Purchase commitment				10,000,000
Web-Hosting Services, November 2022
Long-term Purchase Commitment [Line Items]
Purchase commitment				$ 10,000,000
Cloud Services, July 2022-July 2025
Long-term Purchase Commitment [Line Items]
Purchase commitment		$ 100,000,000
Purchase commitment, term		3 years
Purchase commitment, incurred cost					$ 0