Goodwill and Intangible Assets - Rollforward Goodwill (Details) - USD ($) $ in Millions				3 Months Ended	12 Months Ended
	Oct. 31, 2025	Apr. 30, 2025	Oct. 31, 2023	Dec. 31, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Goodwill Activity
As of beginning of period					$ 6,955	$ 6,955
Impairment	$ (2,000)	$ 0	$ (2,400)	$ 0	(2,012)	0	$ (2,405)
Reclassified as held for sale					(1,305)
As of end of period				6,955	3,638	6,955	6,955
Accumulated impairment losses				$ 2,405	$ 4,417	$ 2,405	$ 2,400