Investments - Schedule of Marketable Securities (Details) - USD ($) $ in Millions	Oct. 31, 2021	Jan. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 4,652	$ 5,738
Unrealized Gains	8	34
Unrealized Losses	(22)	(1)
Fair Value	4,638	5,771
Corporate notes and obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,881	3,321
Unrealized Gains	5	20
Unrealized Losses	(15)	0
Fair Value	2,871	3,341
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	212	205
Unrealized Gains	0	1
Unrealized Losses	(1)	0
Fair Value	211	206
Mortgage-backed obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	258	382
Unrealized Gains	1	5
Unrealized Losses	(2)	0
Fair Value	257	387
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	931	1,096
Unrealized Gains	1	6
Unrealized Losses	(2)	(1)
Fair Value	930	1,101
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	138	242
Unrealized Gains	1	2
Unrealized Losses	0	0
Fair Value	139	244
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	40
Unrealized Gains	0
Unrealized Losses	0
Fair Value	40
Covered bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	181	328
Unrealized Gains	0	0
Unrealized Losses	(2)	0
Fair Value	179	328
Other
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11	164
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	$ 11	$ 164

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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