REVENUES, Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Principal transactions	$ 133	$ 147
Total non-interest revenues	2,593	2,057
All other	16	40
Interest income	225	203
Total revenues	2,818	2,260
Interest expense	(37)	(38)
Net revenues	2,781	2,222
Receivables related to contracts with customers	343		$ 416
Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,382	1,067
Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	558	528
Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	425	381
Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	175	151
Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	111	98
Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	139	132
Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	177	145
Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	113	94
RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	17	21
Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	47	30
Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	425	261
Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	271	149
Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	110	66
Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	44	46
Total other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	51	56
Noninterest income	51	56
Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	35	16
Operating segments | Private Client Group
Disaggregation of Revenue [Line Items]
Principal transactions	11	12
Total non-interest revenues	1,809	1,439
All other	7	5
Interest income	33	30
Total revenues	1,842	1,469
Interest expense	(3)	(2)
Net revenues	1,839	1,467
Operating segments | Private Client Group | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,162	885
Operating segments | Private Client Group | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	397	353
Operating segments | Private Client Group | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	386	341
Operating segments | Private Client Group | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	171	148
Operating segments | Private Client Group | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	111	98
Operating segments | Private Client Group | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	104	95
Operating segments | Private Client Group | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	230	190
Operating segments | Private Client Group | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	114	94
Operating segments | Private Client Group | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	67	64
Operating segments | Private Client Group | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	49	32
Operating segments | Private Client Group | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	13	6
Operating segments | Private Client Group | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Private Client Group | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	13	6
Operating segments | Private Client Group | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Private Client Group | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	7	5
Operating segments | Private Client Group | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Capital Markets
Disaggregation of Revenue [Line Items]
Principal transactions	122	134
Total non-interest revenues	611	451
All other	2	3
Interest income	5	3
Total revenues	616	454
Interest expense	(2)	(2)
Net revenues	614	452
Operating segments | Capital Markets | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	2
Operating segments | Capital Markets | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	159	173
Operating segments | Capital Markets | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	37	39
Operating segments | Capital Markets | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2
Operating segments | Capital Markets | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Capital Markets | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	35	37
Operating segments | Capital Markets | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2
Operating segments | Capital Markets | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Capital Markets | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Capital Markets | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2
Operating segments | Capital Markets | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	412	255
Operating segments | Capital Markets | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	271	149
Operating segments | Capital Markets | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	97	60
Operating segments | Capital Markets | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	44	46
Operating segments | Capital Markets | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	37	19
Operating segments | Capital Markets | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	35	16
Operating segments | Asset Management
Disaggregation of Revenue [Line Items]
Principal transactions	0	0
Total non-interest revenues	236	195
All other	1	1
Interest income	0	0
Total revenues	236	195
Interest expense	0	0
Net revenues	236	195
Operating segments | Asset Management | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	227	188
Operating segments | Asset Management | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	2	2
Operating segments | Asset Management | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2
Operating segments | Asset Management | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2
Operating segments | Asset Management | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Asset Management | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Asset Management | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6	4
Operating segments | Asset Management | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Asset Management | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Asset Management | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6	4
Operating segments | Asset Management | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Asset Management | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Asset Management | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Asset Management | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | Asset Management | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	1	1
Operating segments | Asset Management | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank
Disaggregation of Revenue [Line Items]
Principal transactions	0	1
Total non-interest revenues	6	10
All other	6	9
Interest income	187	168
Total revenues	193	178
Interest expense	(10)	(11)
Net revenues	183	167
Operating segments | RJ Bank | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	0	1
Operating segments | RJ Bank | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Operating segments | RJ Bank | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	6	9
Operating segments | RJ Bank | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Other and intersegment eliminations
Disaggregation of Revenue [Line Items]
Principal transactions	0	0
Total non-interest revenues	(69)	(38)
All other	0	22
Interest income	0	2
Total revenues	(69)	(36)
Interest expense	(22)	(23)
Net revenues	(91)	(59)
Other and intersegment eliminations | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(8)	(8)
Other and intersegment eliminations | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	0	(1)
Other and intersegment eliminations | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	(1)
Other and intersegment eliminations | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	(1)
Other and intersegment eliminations | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Other and intersegment eliminations | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Other and intersegment eliminations | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(61)	(51)
Other and intersegment eliminations | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(1)	0
Other and intersegment eliminations | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(50)	(43)
Other and intersegment eliminations | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(10)	(8)
Other and intersegment eliminations | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Other and intersegment eliminations | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Other and intersegment eliminations | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Other and intersegment eliminations | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Other and intersegment eliminations | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	0	22
Other and intersegment eliminations | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0