Reserves for Credit Losses (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provisions	$ (1,419)	$ 4,730	$ 3,573
Card Member receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	267	619	573
Provisions	(73)	1,015	963
Net write-offs	(129)	(881)	(900)
Other	(1)	7	(17)
Ending Balance	64	267	619
Recoveries	378	386	374
Net (write-offs) recoveries from TDRs	(64)	(47)	(16)
Card Member receivables | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance		126
Ending Balance			126
Card Member receivables | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Decrease in financing receivable, allowance				$ 493
Card Member receivables | Foreign Currency Translation Adjustments
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Foreign currency translation adjustments	$ (1)	$ 5	$ 0