Reserves for Credit Losses (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2020
Reserve for Losses [Roll Forward]
Provisions	$ (1,419)	$ 4,730	$ 3,573
Card Member loans
Reserve for Losses [Roll Forward]
Beginning Balance	5,344	2,383	2,134
Provisions	(1,155)	3,453	2,462
Other	(5)	34	22
Ending Balance	3,305	5,344	2,383
Recoveries	657	568	525
Net (write-offs) recoveries from TDRs	(171)	(134)	(79)
Foreign currency translation adjustments	(6)	35	4
Card Member loans | Principal
Reserve for Losses [Roll Forward]
Net write-offs	(672)	(1,795)	(1,860)
Card Member loans | Interest and fees
Reserve for Losses [Roll Forward]
Net write-offs	$ (207)	(375)	(375)
Cumulative Effect, Period of Adoption, Adjusted Balance | Card Member loans
Reserve for Losses [Roll Forward]
Beginning Balance		$ 4,027
Ending Balance			$ 4,027
Cumulative Effect, Period of Adoption, Adjustment | Card Member loans
Reserve for Losses [Roll Forward]
Increase in financing receivable, allowance				$ 1,643