COMMITMENTS AND CONTINGENCIES - Schedule of Fair Value, Off-balance Sheet Risks (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Financing assets (excluding leases)
Other Commitments [Line Items]
Credit related commitments	$ 56,685	$ 57,567
Standby letters of credit
Other Commitments [Line Items]
Credit related commitments	2,224	2,412
Other letters of credit
Other Commitments [Line Items]
Credit related commitments	104	103
Deferred Purchase Agreements
Other Commitments [Line Items]
Credit related commitments	1,742	2,076
Lessor commitments
Other Commitments [Line Items]
Credit related commitments	$ 551	$ 685