Investments - Schedule of Marketable Securities (Details) - USD ($) $ in Millions	Apr. 30, 2025	Jan. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 6,479	$ 5,215
Unrealized Gains	19	9
Unrealized Losses	(18)	(40)
Fair Value	6,480	5,184
Corporate notes and obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,779	2,574
Unrealized Gains	13	6
Unrealized Losses	(10)	(23)
Fair Value	2,782	2,557
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,148	546
Unrealized Gains	2	0
Unrealized Losses	(3)	(4)
Fair Value	1,147	542
Mortgage-backed obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	144	128
Unrealized Gains	0	0
Unrealized Losses	(4)	(6)
Fair Value	140	122
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,229	1,218
Unrealized Gains	4	3
Unrealized Losses	(1)	(4)
Fair Value	1,232	1,217
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	85	108
Unrealized Gains	0	0
Unrealized Losses	0	(1)
Fair Value	85	107
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	928	506
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	928	506
Covered bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	26	29
Unrealized Gains	0	0
Unrealized Losses	0	(2)
Fair Value	26	27
Other
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	140	106
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	$ 140	$ 106