v3.26.1
COLLATERALIZED AGREEMENTS AND FINANCINGS, Repurchase Agreements (Details) - Maturity overnight and continuous - USD ($)
$ in Millions
Mar. 31, 2026
Sep. 30, 2025
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Repurchase agreements: $ 361 $ 325
Total collateralized financings 1,142 1,111
Government and agency obligations    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Repurchase agreements: 157 125
Agency MBS and agency CMOs    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Repurchase agreements: 204 200
Equity securities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities loaned: $ 781 $ 786