Investments - Schedule of Marketable Securities (Details) - USD ($) $ in Millions	Oct. 31, 2025	Jan. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,331	$ 5,215
Unrealized Gains	15	9
Unrealized Losses	(1)	(40)
Fair Value	2,345	5,184
Corporate notes and obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,431	2,574
Unrealized Gains	10	6
Unrealized Losses	0	(23)
Fair Value	1,441	2,557
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	168	546
Unrealized Gains	2	0
Unrealized Losses	0	(4)
Fair Value	170	542
Mortgage-backed obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	33	128
Unrealized Gains	0	0
Unrealized Losses	(1)	(6)
Fair Value	32	122
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	642	1,218
Unrealized Gains	3	3
Unrealized Losses	0	(4)
Fair Value	645	1,217
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	26	108
Unrealized Gains	0	0
Unrealized Losses	0	(1)
Fair Value	26	107
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	18	506
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	18	506
Covered bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1	29
Unrealized Gains	0	0
Unrealized Losses	0	(2)
Fair Value	1	27
Other
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	12	106
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	$ 12	$ 106

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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