Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2026	Apr. 30, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 3,045	$ 2,621
Other comprehensive income (loss) before reclassifications	(4)	41
Pre-tax loss reclassified from accumulated other comprehensive loss	10	(3)
Tax effects	(8)	(1)
Total other comprehensive income (loss)	(2)	37
Ending balance	3,189	2,617
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(232)	(285)
Total other comprehensive income (loss)	(2)	37
Ending balance	(234)	(248)
Net Unrealized Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(17)	24
Other comprehensive income (loss) before reclassifications	1	(22)
Pre-tax loss reclassified from accumulated other comprehensive loss	10	(3)
Tax effects	(1)	2
Total other comprehensive income (loss)	10	(23)
Ending balance	(7)	1
Net Unrealized Gains (Losses) on Available-for-Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	22	20
Other comprehensive income (loss) before reclassifications	7	1
Pre-tax loss reclassified from accumulated other comprehensive loss	0	0
Tax effects	(6)	0
Total other comprehensive income (loss)	1	1
Ending balance	23	21
Defined Benefit Pension Components
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(27)	(25)
Other comprehensive income (loss) before reclassifications	0	1
Pre-tax loss reclassified from accumulated other comprehensive loss	0	0
Tax effects	0	0
Total other comprehensive income (loss)	0	1
Ending balance	(27)	(24)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(210)	(304)
Other comprehensive income (loss) before reclassifications	(12)	61
Pre-tax loss reclassified from accumulated other comprehensive loss	0	0
Tax effects	(1)	(3)
Total other comprehensive income (loss)	(13)	58
Ending balance	$ (223)	$ (246)