Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, net of tax	$ (77,358)	$ 981
Net unrealized gain on available for sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, before tax	(111,694)	(392)
Accumulated other comprehensive income, tax effect	33,021	116
Accumulated other comprehensive income, net of tax	(78,673)	(276)
Unfunded status of the supplemental retirement plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, before tax	2,481	2,399
Accumulated other comprehensive income, tax effect	(733)	(709)
Accumulated other comprehensive income, net of tax	1,748	1,690
Joint beneficiary agreement liability
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, before tax	(433)	(433)
Accumulated other comprehensive income, tax effect	0
Accumulated other comprehensive income, net of tax	$ (433)	$ (433)