Loans and Card Member Receivables (Details) - USD ($) $ in Millions	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Card Member Loans
Loans segment information
Financing receivables, gross	$ 95,437		$ 88,562
Less: Reserves for credit losses	2,997	$ 2,981	3,305	$ 3,835	$ 4,467	$ 5,344
Financing receivables, net	92,440		85,257
Other Loans
Loans segment information
Less: Reserves for credit losses	38		52
Financing receivables, net	3,983		2,859
Card Member Receivables
Loans segment information
Financing receivables, gross	56,019		53,645
Less: Reserves for credit losses	119	$ 76	64	$ 73	$ 202	$ 267
Financing receivables, net	55,900		53,581
Variable Interest Entity, Primary Beneficiary | Card Member Loans
Loans segment information
Financing receivables, gross	26,834		26,587
Variable Interest Entity, Primary Beneficiary | Card Member Receivables
Loans segment information
Financing receivables, gross	5,769		5,175
GCSG | Card Member Loans
Loans segment information
Financing receivables, gross	74,747		70,467
GCSG | Card Member Receivables
Loans segment information
Financing receivables, gross	21,390		22,392
GCSG | Variable Interest Entity, Primary Beneficiary | Card Member Loans
Loans segment information
Financing receivables, gross	26,800		26,600
GCS | Card Member Loans
Loans segment information
Financing receivables, gross	20,690		18,095
GCS | Card Member Receivables
Loans segment information
Financing receivables, gross	34,629		31,253
GCS | Variable Interest Entity, Primary Beneficiary | Card Member Receivables
Loans segment information
Financing receivables, gross	$ 5,800		$ 5,200