Loans and Card Member Receivables - TDR (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Impaired loans and receivables
Loans over 90 days past due and accruing interest		$ 309
Non-accrual loans		191
Account classified as a TDR in program		1,733
Account classified as a TDR out of program		2,068
Total impaired loans and receivables		4,301
Reserve for Credit Losses - TDRs		$ 504
Accounts Receivable and Loans Textuals
Loans and receivables threshold period for write off		180 days
Account classified as TDR, past due 90 days and still accruing		$ 48
Accounts classified as TDR, non-accrual		17
Out of Program TDR accounts that completed modification programs		1,922
Out of Program TDR accounts not in compliance with modification programs		146
Card Member Loans
Accounts Receivable and Loans Textuals
Loans and receivables threshold period for write off	180 days
Card Member Loans | Consumer
Impaired loans and receivables
Loans over 90 days past due and accruing interest	$ 369	252
Non-accrual loans	272	155
Account classified as a TDR in program		781
Account classified as a TDR out of program		1,098
Total impaired loans and receivables		2,286
Reserve for Credit Losses - TDRs		335
Card Member Loans | Small Business
Impaired loans and receivables
Loans over 90 days past due and accruing interest	109	54
Non-accrual loans	73	34
Account classified as a TDR in program		267
Account classified as a TDR out of program		380
Total impaired loans and receivables		735
Reserve for Credit Losses - TDRs		108
Card Member Loans | Corporate
Impaired loans and receivables
Loans over 90 days past due and accruing interest	0	0
Non-accrual loans	$ 0	0
Account classified as a TDR in program		0
Account classified as a TDR out of program		0
Total impaired loans and receivables		0
Reserve for Credit Losses - TDRs		0
Card Member Receivables
Accounts Receivable and Loans Textuals
Loans and receivables threshold period for write off	180 days
Card Member Receivables | Consumer
Impaired loans and receivables
Loans over 90 days past due and accruing interest	$ 0	0
Non-accrual loans	0	0
Account classified as a TDR in program		257
Account classified as a TDR out of program		179
Total impaired loans and receivables		436
Reserve for Credit Losses - TDRs		20
Card Member Receivables | Small Business
Impaired loans and receivables
Loans over 90 days past due and accruing interest	0	0
Non-accrual loans	0	0
Account classified as a TDR in program		403
Account classified as a TDR out of program		402
Total impaired loans and receivables		805
Reserve for Credit Losses - TDRs		40
Card Member Receivables | Corporate
Impaired loans and receivables
Loans over 90 days past due and accruing interest	0	0
Non-accrual loans	$ 0	0
Account classified as a TDR in program		6
Account classified as a TDR out of program		7
Total impaired loans and receivables		13
Reserve for Credit Losses - TDRs		1
Other Loans
Impaired loans and receivables
Loans over 90 days past due and accruing interest		3
Non-accrual loans		2
Account classified as a TDR in program		19
Account classified as a TDR out of program		2
Total impaired loans and receivables		26
Reserve for Credit Losses - TDRs		$ 0