ALLOWANCE FOR CREDIT LOSSES - Schedule of Allowance for Credit Losses for Other Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	$ 1,865	$ 1,788
Gross credit losses	(17)	(18)
Gross recoveries	4	5
Net credit losses (NCLs)	(13)	(13)
Net reserve builds (releases)	26	(9)
Total provision for credit losses	39	4
Other, net	315	(57)
Allowance for credit losses on other assets at end of quarter	2,206	1,722
Deposits with banks
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	25	31
Gross credit losses	0	0
Gross recoveries	0	0
Net credit losses (NCLs)	0	0
Net reserve builds (releases)	(6)	(3)
Total provision for credit losses	(6)	(3)
Other, net	0	0
Allowance for credit losses on other assets at end of quarter	19	28
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	3	27
Gross credit losses	0	0
Gross recoveries	0	0
Net credit losses (NCLs)	0	0
Net reserve builds (releases)	1	(9)
Total provision for credit losses	1	(9)
Other, net	0	0
Allowance for credit losses on other assets at end of quarter	4	18
All other assets
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	1,837	1,730
Gross credit losses	(17)	(18)
Gross recoveries	4	5
Net credit losses (NCLs)	(13)	(13)
Net reserve builds (releases)	31	3
Total provision for credit losses	44	16
Other, net	315	(57)
Allowance for credit losses on other assets at end of quarter	$ 2,183	$ 1,676