REVENUES, Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Principal transactions	$ 492	$ 462	$ 527
All other	62	78	61
Total non-interest revenues	10,691	9,244	9,800
Interest Income	4,232	3,748	1,508
Total revenues	14,923	12,992	11,308
Interest expense	(2,102)	(1,373)	(305)
Net revenues	12,821	11,619	11,003
Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6,196	5,363	5,563
Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,651	1,459	1,589
Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	575	547	631
Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	519	439	438
Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	557	473	520
Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	2,143	1,921	2,116
Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,314	1,125	833
Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	470	414	427
RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	607	498	202
Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	237	213	204
Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	858	648	1,100
Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	521	418	709
Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	169	120	248
Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	168	110	143
Total other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	180	187	188
Noninterest income	180	187	188
Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	118	109	127
Operating segments | Private Client Group
Disaggregation of Revenue [Line Items]
Principal transactions	112	108	76
All other	27	48	32
Total non-interest revenues	9,098	8,299	7,503
Interest Income	480	455	249
Total revenues	9,578	8,754	7,752
Interest expense	(119)	(100)	(42)
Net revenues	9,459	8,654	7,710
Operating segments | Private Client Group | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5,246	4,545	4,710
Operating segments | Private Client Group | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,519	1,326	1,440
Operating segments | Private Client Group | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	567	540	620
Operating segments | Private Client Group | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	519	439	438
Operating segments | Private Client Group | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	433	347	382
Operating segments | Private Client Group | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	1,631	1,434	1,516
Operating segments | Private Client Group | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,156	2,237	1,207
Operating segments | Private Client Group | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	461	415	428
Operating segments | Private Client Group | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,431	1,591	559
Operating segments | Private Client Group | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	264	231	220
Operating segments | Private Client Group | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	38	35	38
Operating segments | Private Client Group | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Private Client Group | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	38	35	38
Operating segments | Private Client Group | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Private Client Group | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	27	48	32
Operating segments | Private Client Group | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Capital Markets
Disaggregation of Revenue [Line Items]
Principal transactions	371	341	446
All other	4	2	10
Total non-interest revenues	1,466	1,211	1,800
Interest Income	109	88	36
Total revenues	1,575	1,299	1,836
Interest expense	(103)	(85)	(27)
Net revenues	1,472	1,214	1,809
Operating segments | Capital Markets | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	2	3
Operating segments | Capital Markets | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	139	134	144
Operating segments | Capital Markets | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6	5	6
Operating segments | Capital Markets | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Capital Markets | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	133	129	138
Operating segments | Capital Markets | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	510	475	590
Operating segments | Capital Markets | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	13	10	8
Operating segments | Capital Markets | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Capital Markets | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5	4	1
Operating segments | Capital Markets | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	8	6	7
Operating segments | Capital Markets | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	820	613	1,062
Operating segments | Capital Markets | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	521	418	709
Operating segments | Capital Markets | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	131	85	210
Operating segments | Capital Markets | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	168	110	143
Operating segments | Capital Markets | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	122	111	137
Operating segments | Capital Markets | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	118	109	127
Operating segments | Asset Management
Disaggregation of Revenue [Line Items]
Principal transactions	0	0	0
All other	3	2	1
Total non-interest revenues	1,013	875	912
Interest Income	14	10	2
Total revenues	1,027	885	914
Interest expense	0	0	0
Net revenues	1,027	885	914
Operating segments | Asset Management | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	983	846	882
Operating segments | Asset Management | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5	6	7
Operating segments | Asset Management | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5	6	7
Operating segments | Asset Management | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Asset Management | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Asset Management | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	5	6	7
Operating segments | Asset Management | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	22	21	22
Operating segments | Asset Management | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10	1	1
Operating segments | Asset Management | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Asset Management | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12	20	21
Operating segments | Asset Management | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Asset Management | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Asset Management | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Asset Management | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Asset Management | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	3	2	1
Operating segments | Asset Management | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank
Disaggregation of Revenue [Line Items]
Principal transactions	9	15	5
All other	51	41	26
Total non-interest revenues	60	56	31
Interest Income	3,494	3,098	1,209
Total revenues	3,554	3,154	1,240
Interest expense	(1,838)	(1,141)	(156)
Net revenues	1,716	2,013	1,084
Operating segments | Bank | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	9	15	5
Operating segments | Bank | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	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
Operating segments | Bank | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Bank | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	51	41	26
Operating segments | Bank | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Other and intersegment eliminations
Disaggregation of Revenue [Line Items]
Principal transactions	0	(2)	0
All other	(23)	(15)	(8)
Total non-interest revenues	(946)	(1,197)	(446)
Interest Income	135	97	12
Total revenues	(811)	(1,100)	(434)
Interest expense	(42)	(47)	(80)
Net revenues	(853)	(1,147)	(514)
Other and intersegment eliminations | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(34)	(30)	(32)
Other and intersegment eliminations | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(12)	(7)	(2)
Other and intersegment eliminations | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(3)	(4)	(2)
Other and intersegment eliminations | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Other and intersegment eliminations | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(9)	(3)	0
Other and intersegment eliminations | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	(12)	(9)	(2)
Other and intersegment eliminations | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(877)	(1,143)	(404)
Other and intersegment eliminations | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(1)	(2)	(2)
Other and intersegment eliminations | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(829)	(1,097)	(358)
Other and intersegment eliminations | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(47)	(44)	(44)
Other and intersegment eliminations | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Other and intersegment eliminations | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Other and intersegment eliminations | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Other and intersegment eliminations | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Other and intersegment eliminations | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	(23)	(15)	(8)
Other and intersegment eliminations | Affordable housing investments business revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0	$ 0