Loans and Card Member Receivables (Details 1) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Card Member Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 99,038	$ 88,562
Card Member Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	76,966	70,467
Card Member Loans | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	22,018	18,040
Card Member Loans | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	54	55
Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	55,275	53,645
Card Member Receivables | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	20,366	22,392
Card Member Receivables | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	18,969	17,977
Card Member Receivables | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	15,940	13,276
Current | Card Member Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	76,283	69,960
Current | Card Member Loans | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	21,857	17,950
Current | Card Member Receivables | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	20,161	22,279
Current | Card Member Receivables | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	18,722	17,846
30 to 59 Days Past Due | Card Member Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	229	158
30 to 59 Days Past Due | Card Member Loans | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	61	34
30 to 59 Days Past Due | Card Member Receivables | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	77	41
30 to 59 Days Past Due | Card Member Receivables | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	103	59
60 to 89 Days Past Due | Card Member Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	154	112
60 to 89 Days Past Due | Card Member Loans | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	38	19
60 to 89 Days Past Due | Card Member Receivables | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	47	24
60 to 89 Days Past Due | Card Member Receivables | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	57	28
90+ Days Past Due | Card Member Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	300	237
90+ Days Past Due | Card Member Loans | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	62	37
90+ Days Past Due | Card Member Loans | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	0	0
90+ Days Past Due | Card Member Receivables | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	81	48
90+ Days Past Due | Card Member Receivables | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	87	44
90+ Days Past Due | Card Member Receivables | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 98	$ 42