Derivative Financial Instruments - Summary of Carrying Amount Hedged Assets/(Liabilities) (Detail) - Designated as Hedging Instrument [Member] - Interest Rate Swap [Member] - Loans Net Of Unearned Income [Member] - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Carrying Amount of the Hedged Assets/(Liabilities)	$ 80,048	$ 81,397
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	(8,424)	(2,394)
Cumulative Amount of Fair Value Hedging Adjustment Remaining for any Hedged Assets/(Liabilities) for which Hedge Accounting has been Discontinued	$ 0	$ 0