Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jul. 31, 2026	Apr. 30, 2026	Jul. 31, 2025	Apr. 30, 2025	Jul. 31, 2026	Jul. 31, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 3,189	$ 3,045	$ 2,617	$ 2,621	$ 3,045	$ 2,621
Other comprehensive income (loss) before reclassifications					(12)	50
Pre-tax gain reclassified from accumulated other comprehensive loss					21	(17)
Tax effects					(10)	(2)
Total other comprehensive income (loss)	1	(2)	(6)	37	(1)	31
Ending balance	3,383	3,189	2,715	2,617	3,383	2,715
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(234)	(232)	(248)	(285)	(232)	(285)
Total other comprehensive income (loss)	1	(2)	(6)	37
Ending balance	(233)	(234)	(254)	(248)	(233)	(254)
Net Unrealized Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(17)		24	(17)	24
Other comprehensive income (loss) before reclassifications					5	(15)
Pre-tax gain reclassified from accumulated other comprehensive loss					21	(17)
Tax effects					(2)	3
Total other comprehensive income (loss)					24	(29)
Ending balance	7		(5)		7	(5)
Net Unrealized Gains (Losses) on Available-for-Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		22		20	22	20
Other comprehensive income (loss) before reclassifications					5	1
Pre-tax gain reclassified from accumulated other comprehensive loss					1	0
Tax effects					(6)	0
Total other comprehensive income (loss)					0	1
Ending balance	22		21		22	21
Defined Benefit Pension Components
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(27)		(25)	(27)	(25)
Other comprehensive income (loss) before reclassifications					1	1
Pre-tax gain reclassified from accumulated other comprehensive loss					(1)	0
Tax effects					0	0
Total other comprehensive income (loss)					0	1
Ending balance	(27)		(24)		(27)	(24)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		$ (210)		$ (304)	(210)	(304)
Other comprehensive income (loss) before reclassifications					(23)	63
Pre-tax gain reclassified from accumulated other comprehensive loss					0	0
Tax effects					(2)	(5)
Total other comprehensive income (loss)					(25)	58
Ending balance	$ (235)		$ (246)		$ (235)	$ (246)