Comprehensive Income - Summary of Changes in Components of Other Comprehensive Income, Net of Tax (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	$ 1,090,145	$ 796,676	$ 827,014	$ 763,784
Reclassification adjustment for securities gains arising during the period				(6)
Other comprehensive loss, net of tax	(28,109)	1,169	(79,045)	(4,883)
Balance at end of period	1,082,406	814,128	1,082,406	814,128
Net gain on securities reclassified from available for sale to held to maturity	0	2,784	0	2,784
Other comprehensive (loss) income, net	(38,224)	1,656	(107,325)	(7,117)
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(47,672)	5,345	3,264	11,397
Net current period other comprehensive loss		1,169		(4,877)
Other comprehensive loss, net of tax	(28,109)	1,169	(79,045)	(4,883)
Balance at end of period	(75,781)	6,514	(75,781)	6,514
Unrealized Gains (Losses) on Available for Sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period		5,380		11,402
Net current period other comprehensive loss		1,280		(4,736)
Reclassification adjustment for securities gains arising during the period				(6)
Other comprehensive loss, net of tax				(4,742)
Balance at end of period		3,876		3,876
Net gain on securities reclassified from available for sale to held to maturity		(2,784)		(2,784)
Unrealized Gains (Losses) on Available for Sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(49,908)		745
Net current period other comprehensive loss	(27,972)	(1,504)	(78,625)	(7,520)
Reclassification adjustment for securities gains arising during the period			0	(6)
Other comprehensive loss, net of tax	(27,972)		(78,625)	(7,526)
Balance at end of period	(77,880)		(77,880)
Other comprehensive (loss) income, net			(106,759)	(10,916)
Amortization of Gain on Debt Securities Reclassified to Held to Maturity
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	2,236	0	2,519	0
Net current period other comprehensive loss		(116)		(116)
Reclassification adjustment for securities gains arising during the period				0
Other comprehensive loss, net of tax	(137)	(116)	(420)	(116)
Balance at end of period	2,099	2,668	2,099	2,668
Net gain on securities reclassified from available for sale to held to maturity		2,784		2,784
Other comprehensive (loss) income, net	(187)	(158)	(566)	(158)
Unrealized Gains (Losses) on Derivatives
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period		(5)		25
Net current period other comprehensive loss		5		(25)
Reclassification adjustment for securities gains arising during the period				0
Other comprehensive loss, net of tax	0	5	0	(25)
Balance at end of period		0		0
Other comprehensive (loss) income, net	$ 0	8	$ 0	143
Pension Items
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period		(30)		(30)
Net current period other comprehensive loss		0		0
Reclassification adjustment for securities gains arising during the period				0
Other comprehensive loss, net of tax				0
Balance at end of period		$ (30)		$ (30)

OCI, Debt Securities, Held-To-Maturity, Transfer from Available-For-Sale, Gain (Loss), before Adjustment, after Tax

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