FAIR VALUE, Investments in Private Equity Measured at Net Asset Value Per Share (Details) - Other investments - Recurring - USD ($) $ in Millions	Jun. 30, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Private equity investments measured at NAV	$ 73	$ 83
Private equity investments not measured at NAV	30	63
Total private equity investments	103	146
Total equity attributable to Raymond James Financial, Inc.
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Unfunded commitment	9	15
Total private equity investments	81	99
Noncontrolling interests
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Total private equity investments	$ 22	$ 47