FAIR VALUE MEASUREMENT - Items Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Items Measured at Fair Value on a Nonrecurring Basis
Non-marketable equity securities measured using the measurement alternative	$ 7,902	$ 8,040
Nonrecurring | Level 2
Items Measured at Fair Value on a Nonrecurring Basis
Loans held-for-sale	495	457
Other real estate owned	0	0
Loans	0	0
Non-marketable equity securities measured using the measurement alternative	0	0
Total assets	495	457
Nonrecurring | Level 3
Items Measured at Fair Value on a Nonrecurring Basis
Loans held-for-sale	676	1,879
Other real estate owned	4	1
Loans	328	69
Non-marketable equity securities measured using the measurement alternative	359	597
Total assets	1,367	2,546
Fair value | Nonrecurring
Items Measured at Fair Value on a Nonrecurring Basis
Loans held-for-sale	1,171	2,336
Other real estate owned	4	1
Loans	328	69
Non-marketable equity securities measured using the measurement alternative	359	597
Total assets	$ 1,862	$ 3,003