Investments - Schedule of Marketable Securities (Details) - USD ($) $ in Millions	Jul. 31, 2025	Jan. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 5,009	$ 5,215
Unrealized Gains	12	9
Unrealized Losses	(14)	(40)
Fair Value	5,007	5,184
Corporate notes and obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,671	2,574
Unrealized Gains	8	6
Unrealized Losses	(6)	(23)
Fair Value	2,673	2,557
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	527	546
Unrealized Gains	1	0
Unrealized Losses	(2)	(4)
Fair Value	526	542
Mortgage-backed obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	145	128
Unrealized Gains	0	0
Unrealized Losses	(4)	(6)
Fair Value	141	122
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,190	1,218
Unrealized Gains	3	3
Unrealized Losses	(1)	(4)
Fair Value	1,192	1,217
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	68	108
Unrealized Gains	0	0
Unrealized Losses	0	(1)
Fair Value	68	107
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	255	506
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	255	506
Covered bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	20	29
Unrealized Gains	0	0
Unrealized Losses	(1)	(2)
Fair Value	19	27
Other
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	133	106
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	$ 133	$ 106