Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 763,784	$ 725,263	$ 623,739
Net current period other comprehensive income (loss)	(8,133)	9,149	10,086
Net unrealized gain on securities reclassified from available for sale to held to maturity	2,784	0	0
Balance at end of period	827,014	763,784	725,263
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	11,397	2,248	(7,838)
Net current period other comprehensive income (loss)	(8,133)	9,149	10,086
Other comprehensive (loss) income before reclassifications	(8,127)	10,021
Amounts reclassified from accumulated other comprehensive income	(6)	(872)
Net unrealized gain on securities reclassified from available for sale to held to maturity	0
Balance at end of period	3,264	11,397	2,248
Unrealized Gains (Losses)  on Available- for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	11,402	1,936	(8,782)
Net current period other comprehensive income (loss)	(7,873)	9,466	10,718
Other comprehensive (loss) income before reclassifications	(7,867)	10,338
Amounts reclassified from accumulated other comprehensive income	(6)	(872)
Net unrealized gain on securities reclassified from available for sale to held to maturity	(2,784)
Balance at end of period	745	11,402	1,936
Amortization of Gain on Debt Securities Reclassified to Held to Maturity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	0	0	0
Net current period other comprehensive income (loss)	(265)	0	0
Other comprehensive (loss) income before reclassifications	(265)	0
Amounts reclassified from accumulated other comprehensive income	0	0
Net unrealized gain on securities reclassified from available for sale to held to maturity	2,784
Balance at end of period	2,519	0	0
Unrealized Gains  (Losses) on  Derivatives
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	25	317	903
Net current period other comprehensive income (loss)	(25)	(292)	(586)
Other comprehensive (loss) income before reclassifications	(25)	(292)
Amounts reclassified from accumulated other comprehensive income	0	0
Net unrealized gain on securities reclassified from available for sale to held to maturity	0
Balance at end of period	0	25	317
Pension Items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(30)	(5)	41
Net current period other comprehensive income (loss)	30	(25)	(46)
Other comprehensive (loss) income before reclassifications	30	(25)
Amounts reclassified from accumulated other comprehensive income	0	0
Net unrealized gain on securities reclassified from available for sale to held to maturity	0
Balance at end of period	$ 0	$ (30)	$ (5)