Comprehensive Income - Summary of Changes in Components of Other Comprehensive Income, Net of Tax (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	$ 1,089,282	$ 768,065	$ 827,014	$ 763,784
Net current period other comprehensive loss		7,042		(6,046)
Reclassification adjustment for securities gains arising during the period		(6)		(6)
Other comprehensive loss, net of tax	(19,836)	7,036	(50,936)	(6,052)
Balance at end of period	1,090,145	796,676	1,090,145	796,676
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(27,836)	(1,691)	3,264	11,397
Other comprehensive loss, net of tax	(19,836)	7,036	(50,936)	(6,052)
Balance at end of period	(47,672)	5,345	(47,672)	5,345
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	(30,220)	(1,733)	745	11,402
Net current period other comprehensive loss		7,119		(6,016)
Reclassification adjustment for securities gains arising during the period	0	(6)	0	(6)
Other comprehensive loss, net of tax	(19,688)	7,113	(50,653)	(6,022)
Balance at end of period	(49,908)	5,380	(49,908)	5,380
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	2,384		2,519
Other comprehensive loss, net of tax	(148)	0	(283)	0
Balance at end of period	2,236		2,236
Unrealized Gains (Losses) on Derivatives
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period		72		25
Net current period other comprehensive loss		(77)		(30)
Reclassification adjustment for securities gains arising during the period		0		0
Other comprehensive loss, net of tax	$ 0	(77)	$ 0	(30)
Balance at end of period		(5)		(5)
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		0
Other comprehensive loss, net of tax		0		0
Balance at end of period		$ (30)		$ (30)