Customer Deposits (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
U.S.:
Interest-bearing	$ 89,899	$ 83,304
Non-interest-bearing (includes Card Member credit balances of: 2022, $481; 2021, $527)	508	553
Non-U.S.:
Interest-bearing	17	18
Non-interest-bearing (includes Card Member credit balances of: 2022, $489; 2021, $503)	493	507
Total customer deposits	90,917	84,382
Card Member Credit Balances
U.S.:
Non-interest-bearing (includes Card Member credit balances of: 2022, $481; 2021, $527)	481	527
Non-U.S.:
Non-interest-bearing (includes Card Member credit balances of: 2022, $489; 2021, $503)	$ 489	$ 503