Reserves for Credit Losses - Change in Receivables Reserve (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provisions	$ 4,923	$ 2,182	$ (1,419)
Card Member receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	229	64	267
Provisions	880	627	(73)
Net write-offs	(937)	(462)	(129)
Other	2	0	(1)
Ending Balance	174	229	64
Recoveries	297	257	378
Card Member receivables | Foreign Currency Translation Adjustments
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Foreign currency translation adjustments	$ 1	$ 2	$ (1)