COMMITMENTS AND CONTINGENT LIABILITIES - Commitments to Extend Credit (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Commercial and industrial
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount represents credit risk	$ 35,731	$ 32,344
Consumer loan portfolio
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount represents credit risk	19,983	19,270
Commercial real estate
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount represents credit risk	1,865	2,543
Standby letters of credit and guarantees on industrial revenue bonds
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount represents credit risk	743	814
Commercial | Commercial letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract amount represents credit risk	$ 24	$ 9