MORTGAGE BANKING AND OTHER SERVICED LOANS - Changes Related to MSRs - Fair Value Method (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
MSRs
Fair value as of beginning of the period	$ 1,491
Fair value at end of the period	1,397
Residential mortgages
MSRs
Fair value as of beginning of the period	1,491	$ 1,552
Amounts capitalized	27	18
Sales	(72)	0
Changes in unpaid principal balance during the period	(39)	(46)
Changes in fair value during the period	(10)	40
Fair value at end of the period	1,397	$ 1,564
MSR loans	95,200		$ 95,600
Federal Home Loan Mortgage Corporation (FHLMC)
MSRs
MSR loans	$ 10,500