Loans and Leases - Summary of Non-Performing Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings	$ 56	$ 48
Non-Performing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	81	79
Troubled debt restructurings	22	21
Total non-performing loans	103	100
Other real estate owned	26	35
Total non-performing assets	$ 129	$ 135
Non-performing loans / total loans and leases	0.44%	0.45%
Non-performing loans OREO / total loans and leases OREO	0.55%	0.61%
Non-performing assets / total assets	0.37%	0.41%