DERIVATIVES - Derivative Notionals (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Hedging instruments under ASC 815
Derivatives
Derivative notionals	$ 352,678	$ 349,195
Hedging instruments under ASC 815 | Interest rate contracts
Derivatives
Derivative notionals	257,165	255,280
Hedging instruments under ASC 815 | Interest rate swaps
Derivatives
Derivative notionals	257,165	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
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	92,565	92,344
Hedging instruments under ASC 815 | Foreign exchange swaps
Derivatives
Derivative notionals	44,147	48,678
Hedging instruments under ASC 815 | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	48,418	43,666
Hedging instruments under ASC 815 | Foreign exchange contract options | Written
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
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	2,948	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	2,948	1,571
Hedging instruments under ASC 815 | Commodity and other contracts | Written
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contracts | 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
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	48,216,523	45,032,245
Other derivative instruments, Trading derivatives | Interest rate contracts
Derivatives
Derivative notionals	31,346,287	30,565,052
Other derivative instruments, Trading derivatives | Interest rate swaps
Derivatives
Derivative notionals	22,518,303	23,780,711
Other derivative instruments, Trading derivatives | Interest rate futures and forwards
Derivatives
Derivative notionals	3,457,157	2,966,025
Other derivative instruments, Trading derivatives | Interest rate contract options | Written
Derivatives
Derivative notionals	2,776,838	1,937,025
Other derivative instruments, Trading derivatives | Interest rate contract options | Purchased
Derivatives
Derivative notionals	2,593,989	1,881,291
Other derivative instruments, Trading derivatives | Foreign exchange contracts
Derivatives
Derivative notionals	13,408,203	11,669,079
Other derivative instruments, Trading derivatives | Foreign exchange swaps
Derivatives
Derivative notionals	7,545,125	6,746,070
Other derivative instruments, Trading derivatives | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	4,209,683	3,350,341
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Written
Derivatives
Derivative notionals	829,689	789,077
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	823,706	783,591
Other derivative instruments, Trading derivatives | Equity contracts
Derivatives
Derivative notionals	1,512,889	1,213,082
Other derivative instruments, Trading derivatives | Equity swaps
Derivatives
Derivative notionals	291,691	266,115
Other derivative instruments, Trading derivatives | Equity futures and forwards
Derivatives
Derivative notionals	94,385	76,935
Other derivative instruments, Trading derivatives | Equity contract options | Written
Derivatives
Derivative notionals	622,464	482,266
Other derivative instruments, Trading derivatives | Equity contract options | Purchased
Derivatives
Derivative notionals	504,349	387,766
Other derivative instruments, Trading derivatives | Commodity and other contracts
Derivatives
Derivative notionals	355,265	350,257
Other derivative instruments, Trading derivatives | Commodity and other swaps
Derivatives
Derivative notionals	85,144	90,884
Other derivative instruments, Trading derivatives | Commodity and other futures and forwards
Derivatives
Derivative notionals	164,020	165,314
Other derivative instruments, Trading derivatives | Commodity and other contracts | Written
Derivatives
Derivative notionals	54,286	45,862
Other derivative instruments, Trading derivatives | Commodity and other contracts | Purchased
Derivatives
Derivative notionals	51,815	48,197
Other derivative instruments, Trading derivatives | Credit derivatives
Derivatives
Derivative notionals	1,593,879	1,234,775
Other derivative instruments, Trading derivatives | Credit derivatives | Written
Derivatives
Derivative notionals	765,188	593,136
Other derivative instruments, Trading derivatives | Credit derivatives | Purchased
Derivatives
Derivative notionals	$ 828,691	$ 641,639