CREDIT CARD AND OTHER LOANS - Allowance for Loan Loss and Delinquencies (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Receivables	$ 16,537		$ 16,537			$ 16,284
Total credit card and other loans	18,126		18,126			17,399
Total credit card loans - available to settle obligations of consolidated VIEs	12,570		12,570			11,215
Unbilled finance charges	268		268			224
Allowance for credit losses	(2,073)	$ (1,645)	(2,073)	$ (1,645)	$ (1,992)	(1,832)	$ (1,635)	$ (2,008)
Credit card and loan receivables, net	$ 16,053		$ 16,053			15,567
Period an account becomes past due before a proprietary collection scoring algorithm automatically scores the risk of an account becoming further delinquent			30 days
Principal receivables balances contractually delinquent:
Re-aged accounts as percentage of total credit card and loan receivables	1.40%	1.40%	1.50%	1.90%
Modified Credit Card Receivables
Impaired credit card and loan receivables	$ 248		$ 248			281
Allowance for loan loss on impaired credit card receivables	$ 62		$ 62			$ 81
Maximum percentage of credit card receivables to total portfolio	2.00%		2.00%			2.00%
Average recorded investment in impaired credit card receivables	$ 248	$ 339	$ 259	$ 412
Interest income on modified credit card receivables	4	5	$ 11	21
Number of days a loan is contractually past due before resulting in charge-off			180 days
Number of days after notification of creditor's bankruptcy or death when an account is charged-off			60 days
Actual charge-offs for unpaid interest and fees	145	$ 91	$ 429	$ 335
Consolidated Variable Interest Entities
Total credit card loans - available to settle obligations of consolidated VIEs	12,570		12,570			$ 11,215
Credit card loans
Receivables	17,863		$ 17,863			17,217
Modified Credit Card Receivables
Maximum period of time temporary programs' concessions remain in place			12 months
Credit card loans | Maximum
Modified Credit Card Receivables
Number of days after notification of creditor's bankruptcy or death when an account is charged-off			180 days
Installment (other) loans
Receivables	263		$ 263			182
Allowance for credit losses	$ (19)		$ (19)			$ (14)
Period for which interest and fee income accrue until balance, interest and other fees are paid or charged off on installment loan receivables			120 days
Installment (other) loans | Maximum
Period for which interest and fee income accrue until balance, interest and other fees are paid or charged off on installment loan receivables			120 days