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, 2022	Jun. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	$ 74		$ 60	$ 53	$ 55
Gross credit losses	(4)		0	(19)	0
Gross recoveries	0		0	2	0
Net credit losses (NCLs)	(4)		0	(17)	0
Net reserve builds (releases)	69		(3)	59	3
Total provision for credit losses	73		(3)	76	3
Other, net	(2)		1	29	0
Allowance for credit losses on other assets at end of quarter	141	$ 74	58	141	58
Institutional Clients Group
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Other, net		30
Deposits with banks
Financing Receivable, Other Assets, Allowance For Credit Loss [Roll Forward]
Allowance for credit losses on other assets at beginning of quarter	17		24	21	20
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)	23		0	19	5
Total provision for credit losses	23		0	19	5
Other, net	0		0	0	(1)
Allowance for credit losses on other assets at end of quarter	40	17	24	40	24
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	27		8	6	10
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)	45		1	35	(1)
Total provision for credit losses	45		1	35	(1)
Other, net	(3)		0	28	0
Allowance for credit losses on other assets at end of quarter	69	27	9	69	9
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	0	0
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)	0		0	0	0
Total provision for credit losses	0		0	0	0
Other, net	0		0	0	0
Allowance for credit losses on other assets at end of quarter	0	0	0	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	30		28	26	25
Gross credit losses	(4)		0	(19)	0
Gross recoveries	0		0	2	0
Net credit losses (NCLs)	(4)		0	(17)	0
Net reserve builds (releases)	1		(4)	5	(1)
Total provision for credit losses	5		(4)	22	(1)
Other, net	1		1	1	1
Allowance for credit losses on other assets at end of quarter	$ 32	$ 30	$ 25	$ 32	$ 25