Derivatives and Hedging Activities - Summary of Amount of Gain (Loss) Recognized in Interest Income and Other Non-interest Expense in Consolidated Statements of Income Related to Derivative Assets and Liabilities (Detail) - Interest Rate Swap [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivatives not Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized	$ (245)	$ 16	$ 244	$ (243)
Derivatives Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized	(57)		20	(1)
Derivatives Designated as Hedging Instruments [Member] | Fair value adjustments on derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized	(8,953)	(3)	375	(206)
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized	$ 8,896	$ 3	$ (355)	$ 205