NONINTEREST INCOME - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Trust and investment services fees
Disaggregation of Revenue [Line Items]
Trailing commission income	$ 3	$ 4	$ 7	$ 8