Risk Management - Effect of Derivative Contracts on the Income Statement (Details) - Derivatives designated as hedging instruments - Derivatives in fair value hedging relationships - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Location	Interest, net	Interest, net	Interest, net	Interest, net
Gain/(loss) recognized in income on derivatives	$ 160	$ (74)	$ 105	$ (55)
Hedged fixed rate debt
Derivative Instruments, Gain (Loss) [Line Items]
Location	Interest, net	Interest, net	Interest, net	Interest, net
Gain/(loss) recognized in income on derivatives	$ (160)	$ 77	$ (104)	$ 59
Cumulative amount of fair value hedging adjustments to hedged fixed rate debt	$ (132)		$ (132)