ALLOWANCE FOR CREDIT LOSSES - Schedule of Allowance for Credit Losses for Other Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	$ 1,722	$ 528	$ 1,788	$ 123
Gross credit losses	(10)	(24)	(28)	(35)
Gross recoveries	8	5	13	5
Net credit losses (NCLs)	(2)	(19)	(15)	(30)
Net reserve builds (releases)	110	130	101	544
Total provision for credit losses	112	149	116	574
Other, net	79	1	22	(8)
Allowance for credit losses on other assets at end of quarter	1,911	659	1,911	659
Deposits with banks
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	28	135	31	51
Gross credit losses	0	0	0	0
Gross recoveries	0	0	0	0
Net credit losses (NCLs)	0	0	0	0
Net reserve builds (releases)	(8)	(114)	(11)	(29)
Total provision for credit losses	(8)	(114)	(11)	(29)
Other, net	1	0	1	(1)
Allowance for credit losses on other assets at end of quarter	21	21	21	21
Securities borrowed and purchased under agreements to resell
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	18	30	27	36
Gross credit losses	0	0	0	0
Gross recoveries	0	0	0	0
Net credit losses (NCLs)	0	0	0	0
Net reserve builds (releases)	14	0	5	(3)
Total provision for credit losses	14	0	5	(3)
Other, net	1	(4)	1	(7)
Allowance for credit losses on other assets at end of quarter	33	26	33	26
All other assets
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	1,676	363	1,730	36
Gross credit losses	(10)	(24)	(28)	(35)
Gross recoveries	8	5	13	5
Net credit losses (NCLs)	(2)	(19)	(15)	(30)
Net reserve builds (releases)	104	244	107	576
Total provision for credit losses	106	263	122	606
Other, net	77	5	20	0
Allowance for credit losses on other assets at end of quarter	$ 1,857	$ 612	$ 1,857	$ 612