Investments - Schedule of Marketable Securities (Details) - USD ($) $ in Millions	Apr. 30, 2026	Jan. 31, 2026
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,902	$ 2,223
Unrealized Gains	5	16
Unrealized Losses	(5)	(1)
Fair Value	2,902	2,238
Corporate notes and obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,467	1,343
Unrealized Gains	3	10
Unrealized Losses	(3)	0
Fair Value	1,467	1,353
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	673	168
Unrealized Gains	1	2
Unrealized Losses	(1)	0
Fair Value	673	170
Mortgage-backed obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	33	32
Unrealized Gains	0	0
Unrealized Losses	(1)	(1)
Fair Value	32	31
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	550	618
Unrealized Gains	1	4
Unrealized Losses	0	0
Fair Value	551	622
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	29	17
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	29	17
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	94	30
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	94	30
Covered bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1	1
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	1	1
Other
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	55	14
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	$ 55	$ 14

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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