SEGMENT INFORMATION, Information Concerning Operations (Details) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			5
Revenues:
Total net revenues	$ 1,834	$ 1,927	$ 5,911	$ 5,717
Pre-tax income
Total pre-tax income	198	342	796	1,021
Net interest income (expense):
Net interest income	175	248	663	740
Total assets:
Total assets	44,682		44,682		$ 38,830
Goodwill:
Goodwill	465		465		464
Operating segments | Private Client Group
Revenues:
Total net revenues	1,249	1,351	4,158	3,978
Pre-tax income
Total pre-tax income	91	140	414	436
Net interest income (expense):
Net interest income	27	46	106	139
Total assets:
Total assets	11,655		11,655		9,042
Goodwill:
Goodwill	276		276		275
Operating segments | Capital Markets
Revenues:
Total net revenues	323	251	881	781
Pre-tax income
Total pre-tax income	62	24	119	77
Net interest income (expense):
Net interest income	2	0	8	3
Total assets:
Total assets	2,301		2,301		2,287
Goodwill:
Goodwill	120		120		120
Operating segments | Asset Management
Revenues:
Total net revenues	163	177	531	513
Pre-tax income
Total pre-tax income	60	65	206	184
Net interest income (expense):
Net interest income	0	1	1	3
Total assets:
Total assets	367		367		401
Goodwill:
Goodwill	69		69		69
Operating segments | RJ Bank
Revenues:
Total net revenues	178	215	604	630
Pre-tax income
Total pre-tax income	14	138	163	384
Net interest income (expense):
Net interest income	169	208	584	610
Total assets:
Total assets	28,830		28,830		25,516
Operating segments | Other
Revenues:
Total net revenues	(20)	(4)	(72)	(2)
Pre-tax income
Total pre-tax income	(29)	(25)	(106)	(60)
Total assets:
Total assets	1,529		1,529		$ 1,584
Intersegment eliminations
Revenues:
Total net revenues	(59)	(63)	(191)	(183)
Other and intersegment eliminations | Other
Revenues:
Total net revenues	(79)	(67)	(263)	(185)
Net interest income (expense):
Net interest income	$ (23)	$ (7)	$ (36)	$ (15)