Customer Deposits (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
U.S.:
Interest-bearing	$ 121,758	$ 109,119
Non-interest-bearing (includes Card Member credit balances of: 2023, $464; 2022, $605)	514	663
Non-U.S.:
Interest-bearing	14	15
Non-interest-bearing (includes Card Member credit balances of: 2023, $467; 2022, $439)	470	442
Total customer deposits	122,756	110,239
Card Member Credit Balances
U.S.:
Non-interest-bearing (includes Card Member credit balances of: 2023, $464; 2022, $605)	464	605
Non-U.S.:
Non-interest-bearing (includes Card Member credit balances of: 2023, $467; 2022, $439)	$ 467	$ 439