Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2023
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in valuation allowance	$ 57,000,000	$ 9,000,000
Accrued penalties and interest related to unrecognized tax benefits	0	$ 0	$ 0
Unrecorded tax benefit, significant change in unrecognized tax benefits is reasonably possible	0
Domestic Tax Jurisdiction
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating loss carryforwards	2,683,000,000
Domestic Tax Jurisdiction | Research Tax Credit Carryforward
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax credit carryforward	130,000,000
State and Local Jurisdiction
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating loss carryforwards	2,025,000,000
State and Local Jurisdiction | Research Tax Credit Carryforward
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax credit carryforward	86,000,000
UK
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating loss carryforwards	$ 34,000,000