SEGMENT INFORMATION, Information Concerning Operations (Details) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Dec. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) businessSegment	Jun. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | businessSegment				5
Revenues:
Total net revenues		$ 2,471	$ 1,834	$ 7,065	$ 5,911
Pre-tax income
Total pre-tax income		385	198	1,231	796
Net interest income (expense):
Net interest income		165	175	493	663
Total assets:
Total assets		57,161		57,161		$ 47,482
Goodwill:
Goodwill		637		637		466
NWPS
Goodwill:
Goodwill, acquired during period	$ 139
Operating segments | Private Client Group
Revenues:
Total net revenues		1,696	1,249	4,810	4,158
Pre-tax income
Total pre-tax income		195	91	527	414
Net interest income (expense):
Net interest income		29	27	84	106
Total assets:
Total assets		17,949		17,949		12,574
Goodwill:
Goodwill		418		418		277
Operating segments | Capital Markets
Revenues:
Total net revenues		446	323	1,331	881
Pre-tax income
Total pre-tax income		115	62	349	119
Net interest income (expense):
Net interest income		1	2	5	8
Total assets:
Total assets		2,359		2,359		2,336
Goodwill:
Goodwill		150		150		120
Operating segments | Asset Management
Revenues:
Total net revenues		225	163	629	531
Pre-tax income
Total pre-tax income		105	60	275	206
Net interest income (expense):
Net interest income		0	0	0	1
Total assets:
Total assets		389		389		380
Goodwill:
Goodwill		69		69		69
Operating segments | RJ Bank
Revenues:
Total net revenues		169	178	496	604
Pre-tax income
Total pre-tax income		104	14	286	163
Net interest income (expense):
Net interest income		161	169	473	584
Total assets:
Total assets		34,363		34,363		30,356
Operating segments | Other
Revenues:
Total net revenues		2	(20)	(6)	(72)
Pre-tax income
Total pre-tax income		(134)	(29)	(206)	(106)
Net interest income (expense):
Net interest income		(26)	(23)	(69)	(36)
Total assets:
Total assets		2,101		2,101		$ 1,836
Intersegment eliminations
Revenues:
Total net revenues		$ (67)	$ (59)	$ (195)	$ (191)