DERIVATIVES - Derivative Notionals (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative assets, location	Trading account assets	Trading account assets
Derivative liabilities, location	Trading account liabilities	Trading account liabilities
Hedging instruments under ASC 815
Derivatives
Derivative notionals	$ 374,383	$ 349,195
Hedging instruments under ASC 815 | Interest rate contracts
Derivatives
Derivative notionals	277,003	255,280
Hedging instruments under ASC 815 | Interest rate swaps
Derivatives
Derivative notionals	277,003	255,280
Hedging instruments under ASC 815 | Interest rate futures and forwards
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Interest rate contract options | Written options
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Interest rate contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Foreign exchange contracts
Derivatives
Derivative notionals	95,630	92,344
Hedging instruments under ASC 815 | Foreign exchange swaps
Derivatives
Derivative notionals	45,851	48,678
Hedging instruments under ASC 815 | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	49,779	43,666
Hedging instruments under ASC 815 | Foreign exchange contract options | Written options
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contracts
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity futures and forwards
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contract options | Written options
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contracts
Derivatives
Derivative notionals	1,750	1,571
Hedging instruments under ASC 815 | Commodity and other swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other futures and forwards
Derivatives
Derivative notionals	1,750	1,571
Hedging instruments under ASC 815 | Commodity and other contract options | Written options
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives | Written options
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Trading derivatives
Derivatives
Derivative notionals	41,538,477	45,032,245
Other derivative instruments, Trading derivatives | Interest rate contracts
Derivatives
Derivative notionals	25,541,413	30,565,052
Other derivative instruments, Trading derivatives | Interest rate swaps
Derivatives
Derivative notionals	17,077,712	23,780,711
Other derivative instruments, Trading derivatives | Interest rate futures and forwards
Derivatives
Derivative notionals	3,022,127	2,966,025
Other derivative instruments, Trading derivatives | Interest rate contract options | Written options
Derivatives
Derivative notionals	2,753,912	1,937,025
Other derivative instruments, Trading derivatives | Interest rate contract options | Purchased
Derivatives
Derivative notionals	2,687,662	1,881,291
Other derivative instruments, Trading derivatives | Foreign exchange contracts
Derivatives
Derivative notionals	13,229,648	11,669,079
Other derivative instruments, Trading derivatives | Foreign exchange swaps
Derivatives
Derivative notionals	7,943,054	6,746,070
Other derivative instruments, Trading derivatives | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	3,737,063	3,350,341
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Written options
Derivatives
Derivative notionals	778,397	789,077
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	771,134	783,591
Other derivative instruments, Trading derivatives | Equity contracts
Derivatives
Derivative notionals	1,362,973	1,213,082
Other derivative instruments, Trading derivatives | Equity swaps
Derivatives
Derivative notionals	317,117	266,115
Other derivative instruments, Trading derivatives | Equity futures and forwards
Derivatives
Derivative notionals	72,592	76,935
Other derivative instruments, Trading derivatives | Equity contract options | Written options
Derivatives
Derivative notionals	544,315	482,266
Other derivative instruments, Trading derivatives | Equity contract options | Purchased
Derivatives
Derivative notionals	428,949	387,766
Other derivative instruments, Trading derivatives | Commodity and other contracts
Derivatives
Derivative notionals	340,117	350,257
Other derivative instruments, Trading derivatives | Commodity and other swaps
Derivatives
Derivative notionals	82,009	90,884
Other derivative instruments, Trading derivatives | Commodity and other futures and forwards
Derivatives
Derivative notionals	161,811	165,314
Other derivative instruments, Trading derivatives | Commodity and other contract options | Written options
Derivatives
Derivative notionals	49,555	45,862
Other derivative instruments, Trading derivatives | Commodity and other contract options | Purchased
Derivatives
Derivative notionals	46,742	48,197
Other derivative instruments, Trading derivatives | Credit derivatives
Derivatives
Derivative notionals	1,064,326	1,234,775
Other derivative instruments, Trading derivatives | Credit derivatives | Written options
Derivatives
Derivative notionals	496,699	593,136
Other derivative instruments, Trading derivatives | Credit derivatives | Purchased
Derivatives
Derivative notionals	$ 567,627	$ 641,639