REVENUES, Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Principal transactions	$ 561	$ 488	$ 357
Total non-interest revenues	9,087	7,168	6,742
All other	124	21	64
Interest Income	823	1,000	1,281
Total revenues	9,910	8,168	8,023
Interest expense	(150)	(178)	(283)
Net revenues	9,760	7,990	7,740
Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	4,868	3,834	3,451
Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,651	1,468	1,450
Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	683	579	611
Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	438	397	412
Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	530	492	427
Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	2,212	1,956	1,807
Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	635	624	738
Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	406	348	326
RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	76	150	280
Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	153	126	132
Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,143	650	596
Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	639	290	379
Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	332	227	132
Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	172	133	85
Total other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	229	104	150
Noninterest income	229	104	150
Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	105	83	86
Operating segments | Private Client Group
Disaggregation of Revenue [Line Items]
Principal transactions	50	64	74
Total non-interest revenues	6,498	5,420	5,176
All other	25	27	26
Interest Income	123	155	225
Total revenues	6,621	5,575	5,401
Interest expense	(10)	(23)	(42)
Net revenues	6,611	5,552	5,359
Operating segments | Private Client Group | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	4,056	3,162	2,820
Operating segments | Private Client Group | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,496	1,319	1,315
Operating segments | Private Client Group | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	670	567	599
Operating segments | Private Client Group | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	438	397	412
Operating segments | Private Client Group | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	388	355	304
Operating segments | Private Client Group | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	1,546	1,383	1,389
Operating segments | Private Client Group | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	824	807	909
Operating segments | Private Client Group | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	408	348	334
Operating segments | Private Client Group | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	259	330	453
Operating segments | Private Client Group | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	157	129	122
Operating segments | Private Client Group | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	47	41	32
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	47	41	32
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	25	27	26
Operating segments | Private Client Group | Tax credit fund 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	511	427	285
Total non-interest revenues	1,879	1,282	1,079
All other	6	7	4
Interest Income	16	25	38
Total revenues	1,895	1,307	1,117
Interest expense	(10)	(16)	(34)
Net revenues	1,885	1,291	1,083
Operating segments | Capital Markets | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	4	7	6
Operating segments | Capital Markets | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	149	144	129
Operating segments | Capital Markets | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6	7	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	143	137	123
Operating segments | Capital Markets | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	660	571	414
Operating segments | Capital Markets | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	8	6	5
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	1	1	0
Operating segments | Capital Markets | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	7	5	5
Operating segments | Capital Markets | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,096	608	564
Operating segments | Capital Markets | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	639	290	379
Operating segments | Capital Markets | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	285	185	100
Operating segments | Capital Markets | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	172	133	85
Operating segments | Capital Markets | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	111	90	90
Operating segments | Capital Markets | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	105	83	86
Operating segments | Asset Management
Disaggregation of Revenue [Line Items]
Principal transactions	0	0	0
Total non-interest revenues	867	714	688
All other	2	2	2
Interest Income	0	1	3
Total revenues	867	715	691
Interest expense	0	0	0
Net revenues	867	715	691
Operating segments | Asset Management | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	837	688	645
Operating segments | Asset Management | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10	8	10
Operating segments | Asset Management | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10	8	10
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	10	8	10
Operating segments | Asset Management | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	18	16	31
Operating segments | Asset Management | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	1	2
Operating segments | Asset Management | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	3
Operating segments | Asset Management | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	18	15	26
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	2	2	2
Operating segments | Asset Management | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank
Disaggregation of Revenue [Line Items]
Principal transactions	0	1	0
Total non-interest revenues	30	27	26
All other	30	26	26
Interest Income	684	800	975
Total revenues	714	827	1,001
Interest expense	(42)	(62)	(155)
Net revenues	672	765	846
Operating segments | Raymond James Bank | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Insurance and annuity products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Equities, ETFs and fixed income products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	0	1	0
Operating segments | Raymond James Bank | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Merger & acquisition and advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Equity underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Debt underwriting
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Operating segments | Raymond James Bank | Total other
Disaggregation of Revenue [Line Items]
Noninterest income	30	26	26
Operating segments | Raymond James Bank | Tax credit fund 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	(4)	(2)
Total non-interest revenues	(187)	(275)	(227)
All other	61	(41)	6
Interest Income	0	19	40
Total revenues	(187)	(256)	(187)
Interest expense	(88)	(77)	(52)
Net revenues	(275)	(333)	(239)
Other and intersegment eliminations | Asset management and related administrative fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(29)	(23)	(20)
Other and intersegment eliminations | Securities commissions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(4)	(3)	(4)
Other and intersegment eliminations | Mutual and other fund products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(3)	(3)	(4)
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	(1)	0	0
Other and intersegment eliminations | Total brokerage revenues
Disaggregation of Revenue [Line Items]
Total brokerage revenues	(4)	(7)	(6)
Other and intersegment eliminations | Total account and service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(215)	(205)	(207)
Other and intersegment eliminations | Mutual fund and annuity service fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(2)	(1)	(10)
Other and intersegment eliminations | RJBDP fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(184)	(181)	(176)
Other and intersegment eliminations | Client account and other fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(29)	(23)	(21)
Other and intersegment eliminations | Total investment banking
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	1	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	1	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	61	(41)	6
Other and intersegment eliminations | Tax credit fund revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0	$ 0