SEGMENT INFORMATION, Information Concerning Operations (Details) $ in Millions	12 Months Ended
	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Segment Reporting Information, Additional Information:
Number of operating segments | segment	5
Goodwill impairment	$ 0	$ 19	$ 0
Net revenues:
Net revenues	7,990	7,740	7,274
Pre-tax income/(loss):
Total pre-tax income	1,052	1,375	1,311
Net interest income (expense):
Net interest income	822	998	842
Total assets:
Aggregate assets	47,482	38,830
Goodwill and Intangible Assets:
Goodwill	466	464	478
Private Client Group
Segment Reporting Information, Additional Information:
Goodwill impairment		0
Goodwill and Intangible Assets:
Goodwill	277	275	276
Capital Markets
Segment Reporting Information, Additional Information:
Goodwill impairment		19
Goodwill and Intangible Assets:
Goodwill	120	120	133
Asset Management
Segment Reporting Information, Additional Information:
Goodwill impairment		0
Goodwill and Intangible Assets:
Goodwill	69	69	69
Operating segments | Private Client Group
Net revenues:
Net revenues	5,552	5,359	5,093
Pre-tax income/(loss):
Total pre-tax income	539	579	576
Net interest income (expense):
Net interest income	132	183	165
Total assets:
Aggregate assets	12,574	9,042
Goodwill and Intangible Assets:
Goodwill	277	275
Operating segments | Capital Markets
Net revenues:
Net revenues	1,291	1,083	964
Pre-tax income/(loss):
Total pre-tax income	225	110	91
Net interest income (expense):
Net interest income	9	4	4
Total assets:
Aggregate assets	2,336	2,287
Goodwill and Intangible Assets:
Goodwill	120	120
Operating segments | Asset Management
Net revenues:
Net revenues	715	691	654
Pre-tax income/(loss):
Total pre-tax income	284	253	235
Net interest income (expense):
Net interest income	1	3	2
Total assets:
Aggregate assets	380	401
Goodwill and Intangible Assets:
Goodwill	69	69
Operating segments | RJ Bank
Net revenues:
Net revenues	765	846	727
Pre-tax income/(loss):
Total pre-tax income	196	515	492
Net interest income (expense):
Net interest income	738	820	704
Total assets:
Aggregate assets	30,356	25,516
Operating segments | Other
Net revenues:
Net revenues	(82)	5	(15)
Pre-tax income/(loss):
Total pre-tax income	(192)	(82)	(83)
Total assets:
Aggregate assets	1,836	1,584
Operating segments | Other | Employee Severance
Pre-tax income/(loss):
Total pre-tax income	(46)
Intersegment eliminations
Net revenues:
Net revenues	(251)	(244)	(149)
Other and intersegment eliminations | Other
Net revenues:
Net revenues	(333)	(239)	(164)
Net interest income (expense):
Net interest income	(58)	(12)	(33)
Canada
Net revenues:
Net revenues	386	391	381
Pre-tax income/(loss):
Total pre-tax income	29	29	$ 47
Total assets:
Aggregate assets	3,260	2,754
Goodwill and Intangible Assets:
Goodwill	$ 24	$ 23