MORTGAGE BANKING AND OTHER SERVICED LOANS - Changes Related to MSRs - Fair Value Method (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
MSRs
Fair value as of beginning of the period			$ 1,530
Fair value at end of the period	$ 1,524		1,524
Residential mortgages
MSRs
Fair value as of beginning of the period	1,496	$ 1,241	1,530	$ 1,029
Amounts capitalized	36	79	57	174
Servicing rights acquired	0	16	0	16
Changes in unpaid principal balance during the period	(41)	(32)	(82)	(71)
Changes in fair value during the period	33	107	19	263
Fair value at end of the period	$ 1,524	$ 1,411	$ 1,524	$ 1,411