COMMITMENTS AND CONTINGENCIES - Schedule of Outstanding Off-balance sheet Arrangements (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Other Commitments [Line Items]
Commitment amount	$ 96,582	$ 98,314
Commitments to extend credit
Other Commitments [Line Items]
Commitment amount	94,432	96,076
Letters of credit
Other Commitments [Line Items]
Commitment amount	2,036	2,119
Loans sold with recourse
Other Commitments [Line Items]
Commitment amount	95	92
Marketing rights
Other Commitments [Line Items]
Commitment amount	18	23
Risk participation agreements
Other Commitments [Line Items]
Commitment amount	$ 1	$ 4