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, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	$ 659	$ 74	$ 123	$ 53
Gross credit losses	(19)	(4)	(54)	(19)
Gross recoveries	6	0	11	2
Net credit losses (NCLs)	(13)	(4)	(43)	(17)
Net reserve builds (releases)	43	69	587	59
Total provision for credit losses	56	73	630	76
Other, net	(4)	(2)	(12)	29
Allowance for credit losses on other assets at end of quarter	698	141	698	141
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	17	51	21
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)	6	23	(23)	19
Total provision for credit losses	6	23	(23)	19
Other, net	0	0	(1)	0
Allowance for credit losses on other assets at end of quarter	27	40	27	40
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	26	27	36	6
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)	30	45	27	35
Total provision for credit losses	30	45	27	35
Other, net	(3)	(3)	(10)	28
Allowance for credit losses on other assets at end of quarter	53	69	53	69
Brokerage receivables
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter		0		0
Gross credit losses		0		0
Gross recoveries		0		0
Net credit losses (NCLs)		0		0
Net reserve builds (releases)		0		0
Total provision for credit losses		0		0
Other, net		0		0
Allowance for credit losses on other assets at end of quarter		0		0
All other assets
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	612	30	36	26
Gross credit losses	(19)	(4)	(54)	(19)
Gross recoveries	6	0	11	2
Net credit losses (NCLs)	(13)	(4)	(43)	(17)
Net reserve builds (releases)	7	1	583	5
Total provision for credit losses	20	5	626	22
Other, net	(1)	1	(1)	1
Allowance for credit losses on other assets at end of quarter	$ 618	$ 32	$ 618	$ 32