FAIR VALUE, Investments in Private Equity Measured at Net Asset Value Per Share (Details) - Private equity investments - Recurring - USD ($) $ in Millions	Dec. 31, 2022	Sep. 30, 2022
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Private equity investments measured at NAV	$ 94	$ 90
Private equity investments not measured at NAV	5	5
Total private equity investments	99	95
Unfunded commitment	$ 38	$ 39