REVENUES, Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Principal transactions	$ 105	$ 93	$ 202	$ 169
Noninterest Income	1,826	1,610	3,589	3,298
All other	(27)	17	(16)	35
Interest income	285	324	582	640
Total revenues	2,111	1,934	4,171	3,938
Interest expense	(43)	(75)	(94)	(148)
Net revenues	2,068	1,859	4,077	3,790
Receivables related to contracts with customers	319		319		$ 347
Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,006	783	1,961	1,648
Total brokerage revenues
Disaggregation of Revenue [Line Items]
Noninterest Income	515	442	975	906
Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	410	349	773	737
Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	166	148	314	308
Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	99	99	200	203
Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	145	102	259	226
Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	172	191	350	376
Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	88	78	178	159
RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	51	79	109	148
Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	33	34	63	69
Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	148	163	289	300
Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	54	25	104	60
Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	72	121	132	206
Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	22	17	53	34
Total other
Disaggregation of Revenue [Line Items]
Noninterest Income	(15)	31	14	68
Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12	14	30	33
Operating segments | Private Client Group
Disaggregation of Revenue [Line Items]
Principal transactions	17	20	34	39
Noninterest Income	1,457	1,224	2,830	2,534
All other	7	9	16	16
Interest income	45	58	94	114
Total revenues	1,502	1,282	2,924	2,648
Interest expense	(7)	(11)	(15)	(21)
Net revenues	1,495	1,271	2,909	2,627
Operating segments | Private Client Group | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	833	638	1,615	1,345
Operating segments | Private Client Group | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Noninterest Income	384	338	731	702
Operating segments | Private Client Group | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	367	318	697	663
Operating segments | Private Client Group | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	163	145	307	302
Operating segments | Private Client Group | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	99	99	200	203
Operating segments | Private Client Group | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	105	74	190	158
Operating segments | Private Client Group | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	222	231	446	456
Operating segments | Private Client Group | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	88	82	178	165
Operating segments | Private Client Group | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	99	122	204	231
Operating segments | Private Client Group | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	35	27	64	60
Operating segments | Private Client Group | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	11	8	22	15
Operating segments | Private Client Group | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	11	8	22	15
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 | 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	7	9	16	16
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	89	72	171	129
Noninterest Income	286	276	552	527
All other	4	0	4	2
Interest income	10	9	18	19
Total revenues	296	285	570	546
Interest expense	(6)	(8)	(12)	(16)
Net revenues	290	277	558	530
Operating segments | Capital Markets | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	1	3	3
Operating segments | Capital Markets | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Noninterest Income	130	103	245	202
Operating segments | Capital Markets | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	41	31	74	73
Operating segments | Capital Markets | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1	1	4	3
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	40	30	70	70
Operating segments | Capital Markets | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2	3	2
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	0	0	0	0
Operating segments | Capital Markets | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2	3	2
Operating segments | Capital Markets | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	137	156	267	285
Operating segments | Capital Markets | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	43	18	82	45
Operating segments | Capital Markets | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	72	121	132	206
Operating segments | Capital Markets | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	22	17	53	34
Operating segments | Capital Markets | Total other
Disaggregation of Revenue [Line Items]
Noninterest Income	16	14	34	35
Operating segments | Capital Markets | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12	14	30	33
Operating segments | Asset Management
Disaggregation of Revenue [Line Items]
Principal transactions	0	0	0	0
Noninterest Income	184	161	367	334
All other	1	0	1	0
Interest income	0	1	1	2
Total revenues	184	162	368	336
Interest expense	0	0	0	0
Net revenues	184	162	368	336
Operating segments | Asset Management | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	177	149	353	310
Operating segments | Asset Management | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Noninterest Income	2	2	4	5
Operating segments | Asset Management | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2	4	5
Operating segments | Asset Management | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2	2	4	5
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	4	10	9	19
Operating segments | Asset Management | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	1	1	2
Operating segments | Asset Management | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	1	0	2
Operating segments | Asset Management | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	4	8	8	15
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 | Equity underwriting
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 | 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	1	0
Operating segments | Asset Management | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank
Disaggregation of Revenue [Line Items]
Principal transactions	0	0	0	1
Noninterest Income	5	7	11	13
All other	5	7	11	12
Interest income	223	247	454	486
Total revenues	228	254	465	499
Interest expense	(18)	(42)	(39)	(84)
Net revenues	210	212	426	415
Operating segments | RJ Bank | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Noninterest Income	0	0	0	1
Operating segments | RJ Bank | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | RJ Bank | Total other
Disaggregation of Revenue [Line Items]
Noninterest Income	5	7	11	12
Operating segments | RJ Bank | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Operating segments | Other and intersegment eliminations
Disaggregation of Revenue [Line Items]
Net revenues	(44)	0	(52)	2
Other and intersegment eliminations | Other and intersegment eliminations
Disaggregation of Revenue [Line Items]
Principal transactions	(1)	1	(3)	0
Noninterest Income	(106)	(58)	(171)	(110)
All other	(44)	1	(48)	5
Interest income	7	9	15	19
Total revenues	(99)	(49)	(156)	(91)
Interest expense	(12)	(14)	(28)	(27)
Net revenues	(111)	(63)	(184)	(118)
Other and intersegment eliminations | Other and intersegment eliminations | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(5)	(5)	(10)	(10)
Other and intersegment eliminations | Other and intersegment eliminations | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Noninterest Income	(1)	(1)	(5)	(4)
Other and intersegment eliminations | Other and intersegment eliminations | Subtotal securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	(2)	(2)	(4)
Other and intersegment eliminations | Other and intersegment eliminations | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	(1)	(2)
Other and intersegment eliminations | 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 | Other and intersegment eliminations | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	(2)	(1)	(2)
Other and intersegment eliminations | Other and intersegment eliminations | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(56)	(52)	(108)	(101)
Other and intersegment eliminations | Other and intersegment eliminations | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	(5)	(1)	(8)
Other and intersegment eliminations | Other and intersegment eliminations | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(48)	(44)	(95)	(85)
Other and intersegment eliminations | Other and intersegment eliminations | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(8)	(3)	(12)	(8)
Other and intersegment eliminations | Other and intersegment eliminations | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	(1)	0	0
Other and intersegment eliminations | Other and intersegment eliminations | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	(1)	0	0
Other and intersegment eliminations | 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 | Other and intersegment eliminations | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Other and intersegment eliminations | Other and intersegment eliminations | Total other
Disaggregation of Revenue [Line Items]
Noninterest Income	(44)	1	(48)	5
Other and intersegment eliminations | Other and intersegment eliminations | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0	$ 0	$ 0