DEBT - Short-Term Borrowings (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Short-term Debt [Line Items]
Commercial paper	$ 20,922	$ 25,530
Other borrowings	19,508	21,566
Total short-term borrowings	40,430	47,096
Collateralized short-term advances from Federal Home Loan Bank	10,000	12,000
Bank
Short-term Debt [Line Items]
Commercial paper	11,108	11,185
Broker-dealer and other
Short-term Debt [Line Items]
Commercial paper	$ 9,814	$ 14,345