Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Non-Recurring Basis (Detail) - Non-recurring Basis - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans and leases	$ 31,049	$ 5,210
Other real estate owned	63	663
Bank-owned premises	1,900
Real estate loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans and leases	41,400	3,500
Commercial and industrial loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans and leases	12,500	1,700
Quoted Prices in Active Markets for Identical Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans and leases	0	0
Other real estate owned	0	0
Bank-owned premises	0
Significant Observable Inputs with No Active Market with Identical Characteristics
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans and leases	0	3,253
Other real estate owned	0	663
Bank-owned premises	0
Significant Unobservable Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans and leases	31,049	1,957
Other real estate owned	63	$ 0
Bank-owned premises	$ 1,900