ALLOWANCE FOR CREDIT LOSSES - Schedule of Allowance for Credit Losses for Other Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	$ 1,911	$ 659	$ 1,788	$ 123
Gross credit losses	(14)	(19)	(42)	(54)
Gross recoveries	8	6	21	11
Net credit losses (NCLs)	(6)	(13)	(21)	(43)
Net reserve builds (releases)	104	43	205	587
Total provision for credit losses	110	56	226	630
Other, net	(146)	(4)	(124)	(12)
Allowance for credit losses on other assets at end of quarter	1,869	698	1,869	698
Deposits with banks
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	21	21	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)	2	6	(9)	(23)
Total provision for credit losses	2	6	(9)	(23)
Other, net	0	0	1	(1)
Allowance for credit losses on other assets at end of quarter	23	27	23	27
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	33	26	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)	(27)	30	(22)	27
Total provision for credit losses	(27)	30	(22)	27
Other, net	(2)	(3)	(1)	(10)
Allowance for credit losses on other assets at end of quarter	4	53	4	53
All other assets
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	1,857	612	1,730	36
Gross credit losses	(14)	(19)	(42)	(54)
Gross recoveries	8	6	21	11
Net credit losses (NCLs)	(6)	(13)	(21)	(43)
Net reserve builds (releases)	129	7	236	583
Total provision for credit losses	135	20	257	626
Other, net	(144)	(1)	(124)	(1)
Allowance for credit losses on other assets at end of quarter	$ 1,842	$ 618	$ 1,842	$ 618