CONDENSED FINANCIAL INFORMATION (PARENT COMPANY ONLY), Condensed Statement of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	$ 818	$ 1,034	$ 857
Adjustments to reconcile net income to net cash provided by operating activities:
Other	92	51	17
Net change in:
Accrued compensation and benefits	70	80	132
Net cash provided by operating activities	4,054	577	884
Cash flows from investing activities:
Net cash used in investing activities	(4,985)	(1,897)	(3,476)
Cash flows from financing activities:
Purchases of treasury stock	(272)	(778)	(62)
Dividends on common stock	(205)	(191)	(151)
Net cash provided by/(used in) financing activities	4,593	1,373	1,420
Cash and cash equivalents and cash and cash equivalents segregated pursuant to regulations at beginning of year	5,971	5,941	7,146
Cash and cash equivalents and cash and cash equivalents segregated pursuant to regulations at end of year	9,634	5,971	5,941
Cash and cash equivalents	5,390	3,957	3,500
Cash segregated pursuant to regulations	4,244	2,014	2,441
Supplemental disclosures of cash flow information:
Cash paid for interest	164	283	201
Cash received for income taxes, net	246	390	231
RJF Parent Company
Cash flows from operating activities:
Net income	818	1,034	857
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on investments	4	4	1
Unrealized gain on company-owned life insurance policies, net of expenses	(50)	(5)	(37)
Equity in undistributed net income of subsidiaries	(134)	(292)	(598)
Other	102	100	114
Net change in:
Assets segregated pursuant to regulations	0	0	(1)
Intercompany receivables	126	(51)	6
Other assets	24	(16)	49
Intercompany payables	(70)	(22)	88
Other payables	24	(1)	13
Accrued compensation and benefits	73	34	66
Net cash provided by operating activities	917	785	558
Cash flows from investing activities:
Investments in subsidiaries	(106)	(24)	(205)
(Advances to)/repayments from subsidiaries, net	(885)	63	4
Proceeds from sales of investments	9	3	12
Purchase of investments in company-owned life insurance policies, net	(55)	(44)	(70)
Net cash used in investing activities	(1,037)	(2)	(259)
Cash flows from financing activities:
Proceeds from senior note issuances, net of debt issuance costs paid	494	0	0
Exercise of stock options and employee stock purchases	62	65	63
Purchases of treasury stock	(272)	(778)	(62)
Dividends on common stock	(205)	(191)	(151)
Net cash provided by/(used in) financing activities	79	(904)	(150)
Net increase/(decrease) in cash and cash equivalents	(41)	(121)	149
Cash and cash equivalents and cash and cash equivalents segregated pursuant to regulations at beginning of year	596	717	568
Cash and cash equivalents and cash and cash equivalents segregated pursuant to regulations at end of year	555	596	717
Cash and cash equivalents	478	540	695
Cash segregated pursuant to regulations	77	56	22
Supplemental disclosures of cash flow information:
Cash paid for interest	72	78	78
Cash received for income taxes, net	32	42	163
Supplemental disclosures of noncash investing activity:
Investments in subsidiaries, net	0	(43)	0
RJF Credit Facility
Cash flows from financing activities:
Proceeds from borrowings on the RJF Credit Facility	0	300	300
Repayment of borrowings on the RJF Credit Facility	$ 0	$ (300)	$ (300)