REVENUES (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Principal transactions	$ 116	$ 105	$ 369	$ 364
All other	21	36	45	65
Total non-interest revenues	2,705	2,306	7,761	6,748
Interest income	1,057	987	3,159	2,729
Total revenues	3,762	3,293	10,920	9,477
Interest expense	(534)	(386)	(1,561)	(911)
Net revenues	3,228	2,907	9,359	8,566
Receivables related to contracts with customers	595		595		$ 519
Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,611	1,373	4,534	3,917
Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	416	356	1,213	1,077
Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	144	137	424	404
Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	130	103	382	320
Equities, exchange-traded funds (“ETFs”) and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	142	116	407	353
Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	532	461	1,582	1,441
Account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	328	264	982	811
Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	120	103	345	306
RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	149	107	461	344
Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	59	54	176	161
Investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	183	151	543	446
Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	91	88	316	277
Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	43	35	111	96
Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	49	28	116	73
Total other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	51	57	120	133
Noninterest income	51	57	120	133
Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	30	21	75	68
Operating segments | Private Client Group
Disaggregation of Revenue [Line Items]
Principal transactions	26	25	84	81
All other	13	25	23	40
Total non-interest revenues	2,327	2,093	6,710	6,125
Interest income	121	114	361	340
Total revenues	2,448	2,207	7,071	6,465
Interest expense	(32)	(25)	(88)	(76)
Net revenues	2,416	2,182	6,983	6,389
Operating segments | Private Client Group | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,364	1,164	3,838	3,319
Operating segments | Private Client Group | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	383	324	1,114	977
Operating segments | Private Client Group | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	142	135	419	398
Operating segments | Private Client Group | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	130	103	382	320
Operating segments | Private Client Group | Equities, exchange-traded funds (“ETFs”) and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	111	86	313	259
Operating segments | Private Client Group | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	409	349	1,198	1,058
Operating segments | Private Client Group | Account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	531	546	1,622	1,681
Operating segments | Private Client Group | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	118	103	339	306
Operating segments | Private Client Group | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	347	384	1,088	1,200
Operating segments | Private Client Group | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	66	59	195	175
Operating segments | Private Client Group | Investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10	9	29	27
Operating segments | Private Client Group | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Private Client Group | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10	9	29	27
Operating segments | Private Client Group | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Private Client Group | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	13	25	23	40
Operating segments | Private Client Group | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Capital Markets
Disaggregation of Revenue [Line Items]
Principal transactions	87	78	278	274
All other	2	0	3	1
Total non-interest revenues	328	276	984	872
Interest income	32	21	81	65
Total revenues	360	297	1,065	937
Interest expense	(30)	(21)	(76)	(64)
Net revenues	330	276	989	873
Operating segments | Capital Markets | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	1	1	2
Operating segments | Capital Markets | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	34	32	105	100
Operating segments | Capital Markets | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	1	4	4
Operating segments | Capital Markets | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Capital Markets | Equities, exchange-traded funds (“ETFs”) and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	33	31	101	96
Operating segments | Capital Markets | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	121	110	383	374
Operating segments | Capital Markets | Account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	3	8	8
Operating segments | Capital Markets | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Capital Markets | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	1	4	3
Operating segments | Capital Markets | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	2	4	5
Operating segments | Capital Markets | Investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	173	141	514	419
Operating segments | Capital Markets | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	91	88	316	277
Operating segments | Capital Markets | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	33	25	82	69
Operating segments | Capital Markets | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	49	28	116	73
Operating segments | Capital Markets | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	32	21	78	69
Operating segments | Capital Markets | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	30	21	75	68
Operating segments | Asset Management
Disaggregation of Revenue [Line Items]
Principal transactions	0	0	0	0
All other	1	0	2	2
Total non-interest revenues	261	224	742	642
Interest income	4	2	10	7
Total revenues	265	226	752	649
Interest expense	0	0	0	0
Net revenues	265	226	752	649
Operating segments | Asset Management | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	254	217	720	620
Operating segments | Asset Management | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	2	4	4
Operating segments | Asset Management | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	2	4	4
Operating segments | Asset Management | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Asset Management | Equities, exchange-traded funds (“ETFs”) and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Asset Management | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	1	2	4	4
Operating segments | Asset Management | Account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5	5	16	16
Operating segments | Asset Management | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	0	7	1
Operating segments | Asset Management | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Asset Management | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3	5	9	15
Operating segments | Asset Management | Investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Asset Management | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Asset Management | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Asset Management | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Asset Management | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	1	0	2	2
Operating segments | Asset Management | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank
Disaggregation of Revenue [Line Items]
Principal transactions	3	3	7	11
All other	9	14	31	33
Total non-interest revenues	12	17	38	44
Interest income	867	826	2,607	2,251
Total revenues	879	843	2,645	2,295
Interest expense	(461)	(329)	(1,362)	(733)
Net revenues	418	514	1,283	1,562
Operating segments | Bank | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Equities, exchange-traded funds (“ETFs”) and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	3	3	7	11
Operating segments | Bank | Account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	9	14	31	33
Operating segments | Bank | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Other and intersegment eliminations
Disaggregation of Revenue [Line Items]
Principal transactions	0	(1)	0	(2)
All other	(4)	(3)	(14)	(11)
Total non-interest revenues	(223)	(304)	(713)	(935)
Interest income	33	24	100	66
Total revenues	(190)	(280)	(613)	(869)
Interest expense	(11)	(11)	(35)	(38)
Net revenues	(201)	(291)	(648)	(907)
Other and intersegment eliminations | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(7)	(9)	(25)	(24)
Other and intersegment eliminations | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(2)	(2)	(10)	(4)
Other and intersegment eliminations | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	(1)	(3)	(2)
Other and intersegment eliminations | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Other and intersegment eliminations | Equities, exchange-traded funds (“ETFs”) and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(2)	(1)	(7)	(2)
Other and intersegment eliminations | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	(2)	(3)	(10)	(6)
Other and intersegment eliminations | Account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(210)	(290)	(664)	(894)
Other and intersegment eliminations | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	(1)	(1)
Other and intersegment eliminations | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(199)	(278)	(631)	(859)
Other and intersegment eliminations | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(11)	(12)	(32)	(34)
Other and intersegment eliminations | Investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	1	0	0
Other and intersegment eliminations | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Other and intersegment eliminations | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	1	0	0
Other and intersegment eliminations | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Other and intersegment eliminations | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	(4)	(3)	(14)	(11)
Other and intersegment eliminations | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0	$ 0	$ 0