REVENUES, Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Principal transactions	$ 127	$ 142	$ 259	$ 275
All other	9	12	29	28
Total non-interest revenues	2,242	2,469	4,442	5,062
Interest income	915	242	1,742	467
Total revenues	3,157	2,711	6,184	5,529
Interest expense	(284)	(38)	(525)	(75)
Net revenues	2,873	2,673	5,659	5,454
Receivables related to contracts with customers	540		540		$ 511
Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,302	1,464	2,544	2,846
Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	496	564	980	1,122
Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	369	422	721	847
Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	137	169	267	344
Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	113	110	217	221
Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	119	143	237	282
Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	258	179	547	356
Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	105	109	203	222
RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	100	20	237	37
Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	53	50	107	97
Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	154	235	295	660
Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	87	139	189	410
Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	38	61	61	171
Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	29	35	45	79
Total other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	32	27	76	78
Noninterest income	32	27	76	78
Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	23	15	47	50
Operating segments | Private Client Group
Disaggregation of Revenue [Line Items]
Principal transactions	28	16	56	27
All other	9	6	15	13
Total non-interest revenues	2,056	1,888	4,032	3,697
Interest income	117	37	226	70
Total revenues	2,173	1,925	4,258	3,767
Interest expense	(29)	(3)	(51)	(6)
Net revenues	2,144	1,922	4,207	3,761
Operating segments | Private Client Group | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,102	1,245	2,155	2,407
Operating segments | Private Client Group | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	364	397	709	794
Operating segments | Private Client Group | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	336	381	653	767
Operating segments | Private Client Group | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	135	166	263	337
Operating segments | Private Client Group | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	113	110	217	221
Operating segments | Private Client Group | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	88	105	173	209
Operating segments | Private Client Group | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	572	231	1,135	461
Operating segments | Private Client Group | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	105	109	203	223
Operating segments | Private Client Group | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	411	69	816	136
Operating segments | Private Client Group | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	56	53	116	102
Operating segments | Private Client Group | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	9	9	18	22
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	9	9	18	22
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	9	6	15	13
Operating segments | Private Client Group | Tax credit fund 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	96	126	196	248
All other	1	1	1	3
Total non-interest revenues	301	411	596	1,022
Interest income	21	5	44	10
Total revenues	322	416	640	1,032
Interest expense	(20)	(3)	(43)	(5)
Net revenues	302	413	597	1,027
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 | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	130	166	264	325
Operating segments | Capital Markets | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	34	40	68	77
Operating segments | Capital Markets | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2	3	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, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	32	38	65	73
Operating segments | Capital Markets | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2	5	4
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	0	2	0
Operating segments | Capital Markets | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	2	3	4
Operating segments | Capital Markets | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	145	226	278	638
Operating segments | Capital Markets | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	87	139	189	410
Operating segments | Capital Markets | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	29	52	44	149
Operating segments | Capital Markets | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	29	35	45	79
Operating segments | Capital Markets | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	24	16	48	53
Operating segments | Capital Markets | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	23	15	47	50
Operating segments | Asset Management
Disaggregation of Revenue [Line Items]
Principal transactions	0	0	0	0
All other	0	0	2	1
Total non-interest revenues	213	234	418	470
Interest income	3	0	5	0
Total revenues	216	234	423	470
Interest expense	0	0	0	0
Net revenues	216	234	423	470
Operating segments | Asset Management | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	206	226	403	453
Operating segments | Asset Management | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	1	2	2	4
Operating segments | Asset Management | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	2	2	4
Operating segments | Asset Management | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	2	2	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, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Asset Management | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6	6	11	12
Operating segments | Asset Management | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	0	1	0
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	5	6	10	12
Operating segments | Asset Management | Total 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	0	0	2	1
Operating segments | Asset Management | Tax credit fund 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	4	0	8	0
All other	6	8	19	14
Total non-interest revenues	10	8	27	14
Interest income	749	199	1,425	386
Total revenues	759	207	1,452	400
Interest expense	(219)	(10)	(404)	(20)
Net revenues	540	197	1,048	380
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 | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	4	0	8	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, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Bank | Total 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 | Total 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	6	8	19	14
Operating segments | Bank | Tax credit fund 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	(1)	0	(1)	0
All other	(7)	(3)	(8)	(3)
Total non-interest revenues	(338)	(72)	(631)	(141)
Interest income	25	1	42	1
Total revenues	(313)	(71)	(589)	(140)
Interest expense	(16)	(22)	(27)	(44)
Net revenues	(329)	(93)	(616)	(184)
Other and intersegment eliminations | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(6)	(8)	(15)	(16)
Other and intersegment eliminations | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	(3)	(1)	(3)	(1)
Other and intersegment eliminations | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(2)	(1)	(2)	(1)
Other and intersegment eliminations | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(1)	(1)	(1)	(1)
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, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(1)	0	(1)	0
Other and intersegment eliminations | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(322)	(60)	(604)	(121)
Other and intersegment eliminations | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(1)	0	(1)	(1)
Other and intersegment eliminations | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(312)	(49)	(581)	(99)
Other and intersegment eliminations | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(9)	(11)	(22)	(21)
Other and intersegment eliminations | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	(1)	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	0	(1)	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	(7)	(3)	(8)	(3)
Other and intersegment eliminations | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0	$ 0	$ 0