COMMITMENTS, CONTINGENCIES AND GUARANTEES, Summary of Off-Balance Sheet Risks (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
SBL and other consumer lines of credit	$ 56,048	$ 44,057
Commercial lines of credit	5,441	4,630
Unfunded lending commitments	716	640
Standby letters of credit	$ 217	$ 111