LOANS AND LEASES - Schedule of Amortized Cost of Loans (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total net unamortized discount	$ 1,688	$ 2,036
Non-PCD
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferred fees, including unamortized costs and unearned fees on non-PCD loans	(86)	(72)
Total net unamortized discount	1,577	1,860
PCD
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total net unamortized discount	$ 111	$ 176