MORTGAGE BANKING AND OTHER SERVICED LOANS - Changes Related to MSRs - Fair Value Method (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
MSRs
Fair value as of beginning of period	$ 1,552
Fair value at end of the period	1,491	$ 1,552
Residential mortgages
MSRs
Fair value as of beginning of period	1,552	1,530
Amounts capitalized	106	127
Sales	(99)	0
Changes in unpaid principal balance during the period	(176)	(166)
Changes in fair value during the period	108	61
Fair value at end of the period	1,491	1,552
MSR loans	95,600	$ 97,400
Federal Home Loan Mortgage Corporation (FHLMC)
MSRs
MSR loans	$ 17,800