CREDIT CARD AND OTHER LOANS - Credit Quality on Amortized Cost Basis (Details) - USD ($) $ in Billions	Jun. 30, 2022	Dec. 31, 2021
Credit Quality
Customer accounts as a percentage of total credit card loans balance for which a Vantage credit score is not available	0.30%	0.10%
Unused credit card lines available to cardholders	$ 99.5	$ 112.1
Installment (other) loans | FICO Score, From 660 and Above
Credit Quality
Percentage of total amortized cost basis of revolving loan receivables outstanding	86	84
Installment (other) loans | FICO Score Below 660
Credit Quality
Percentage of total amortized cost basis of revolving loan receivables outstanding	14	16
Credit Card Receivable | No Score | Credit Score, from 661 or Higher
Credit Quality
Percentage of amortized cost basis of credit card receivables outstanding	61.00%	62.00%
Credit Card Receivable | No Score | Credit Score, From 601 to 660
Credit Quality
Percentage of amortized cost basis of credit card receivables outstanding	27.00%	26.00%
Credit Card Receivable | No Score | Credit Score, From 600 or Less
Credit Quality
Percentage of amortized cost basis of credit card receivables outstanding	12.00%	12.00%