BORROWINGS - Schedule of Borrowings (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total short-term borrowings	$ 2,039	$ 1,108
Long-term borrowings and lease obligation	17,234	19,417
Total borrowings	19,273	20,525
Senior unsecured
Debt Instrument [Line Items]
Long-term borrowings	$ 15,467	$ 17,509
Average Rate	4.03%	3.99%
Subordinated notes and other
Debt Instrument [Line Items]
Long-term borrowings	$ 1,330	$ 1,383
Average Rate	4.43%	4.43%
Other
Debt Instrument [Line Items]
Long-term borrowings and lease obligation	$ 437	$ 525
Senior unsecured
Debt Instrument [Line Items]
Current portion of long-term borrowings	$ 1,952	$ 1,044
Average Rate	4.03%	3.99%
Subordinated notes and other
Debt Instrument [Line Items]
Current portion of long-term borrowings	$ 87	$ 27
Other short-term borrowings
Debt Instrument [Line Items]
Other short-term borrowings	$ 0	$ 37