Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,145	$ 849
Other comprehensive income (loss) before reclassifications	0	(11)
Pre-tax gains reclassified from accumulated other comprehensive loss	(22)	(5)
Tax effects	7	(8)
Total other comprehensive loss	(15)	(24)
Ending balance	897	681
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(185)	(124)
Ending balance	(200)	(148)
Net Unrealized Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	64	24
Other comprehensive income (loss) before reclassifications	7	65
Pre-tax gains reclassified from accumulated other comprehensive loss	(22)	(2)
Tax effects	2	(8)
Total other comprehensive loss	(13)	55
Ending balance	51	79
Net Unrealized Gains (Losses) on Available-for-Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	18	18
Other comprehensive income (loss) before reclassifications	2	(1)
Pre-tax gains reclassified from accumulated other comprehensive loss	0	0
Tax effects	0	0
Total other comprehensive loss	2	(1)
Ending balance	20	17
Defined Benefit Pension Components
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(19)	(16)
Other comprehensive income (loss) before reclassifications	0	0
Pre-tax gains reclassified from accumulated other comprehensive loss	0	(3)
Tax effects	0	0
Total other comprehensive loss	0	(3)
Ending balance	(19)	(19)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(248)	(150)
Other comprehensive income (loss) before reclassifications	(9)	(75)
Pre-tax gains reclassified from accumulated other comprehensive loss	0	0
Tax effects	5	0
Total other comprehensive loss	(4)	(75)
Ending balance	$ (252)	$ (225)