Geographic Information - Long-Lived Assets (Details) - USD ($) $ in Millions	Jul. 31, 2025	Jan. 31, 2025
Long-Lived Assets [Line Items]
Total long-lived assets	$ 1,840	$ 1,575
United States
Long-Lived Assets [Line Items]
Total long-lived assets	1,144	1,197
Ireland
Long-Lived Assets [Line Items]
Total long-lived assets	517	215
Other countries
Long-Lived Assets [Line Items]
Total long-lived assets	$ 179	$ 163

Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-41

Name:	us-gaap_NoncurrentAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant