LEASES, Balances Related to Leases on Consolidated Statements of Financial Condition (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Leases [Abstract]
ROU lease assets (included in “Other assets”)	$ 583	$ 568
ROU lease assets, location	Other assets	Other assets
Lease liabilities (included in “Other payables”)	$ 538	$ 533
Lease liabilities, location	Other Liabilities	Other Liabilities