MORTGAGE BANKING AND OTHER SERVICED LOANS - Residential Mortgage Loan Sales (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Residential mortgages
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Cash proceeds from residential mortgage loans sold with servicing retained	$ 2,734	$ 1,807	$ 4,392	$ 3,295
Mortgage banking fees
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Gain on sales	21	15	37	30
Contractually specified servicing, late and other ancillary fees	$ 69	$ 77	$ 139	$ 156