Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) and Related Tax Effects (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income (loss)	$ (1,818)	$ (794)
Accumulated other comprehensive income, net of tax	(1,999)		$ (181)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)	(2,114)		249
Other comprehensive Loss, Tax effect	478		(64)
Total other comprehensive income (loss)	(1,636)		185
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)	(635)		(646)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)	214		222
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)	(421)		(424)
Other comprehensive Loss, Tax effect	58		58
Total other comprehensive income (loss)	$ (363)		$ (366)