Derivative Financial Instruments - Summary of Notional Balance and Fair Values of Derivatives Outstanding (Detail) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Notional Amount	$ 123,234,000	$ 124,926,000
Derivative Assets	5,213,000	7,172,000
Derivative Liabilities	5,942,000	8,317,000
Cash collateral, Derivative Liabilities	(6,110,000)	(8,440,000)
Netting adjustments, Derivative Assets	239,000	123,000
Netting adjustments, Derivative Liabilities	239,000	123,000
Net amount presented in Balance Sheet, Derivative Assets	5,452,000	7,295,000
Net amount presented in Balance Sheet, Derivative Liabilities	71,000
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	5,474,000	5,585,000
Derivative Liabilities	326,000	497,000
Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	5,474,000	5,585,000
Derivative Liabilities	326,000	497,000
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	117,760,000	119,341,000
Derivative Assets	5,213,000	7,172,000
Derivative Liabilities	5,616,000	7,820,000
Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	117,760,000	119,341,000
Derivative Assets	5,213,000	7,172,000
Derivative Liabilities	$ 5,616,000	$ 7,820,000