LOANS AND LEASES - Non-Performing Assets (Detail) - Non-Performing [Member] - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 157	$ 170
Total non-performing loans	157	170
Other real estate owned	9	10
Non Performing Assets	$ 166	$ 180
Non-performing loans / total loans and leases	0.62%	0.67%
Non-performing assets + 90 days past due + OREO / total loans and leases + OREO	0.68%	0.77%
Past due	90 days	90 days