Other Comprehensive Income (Loss) - Schedule of Components of OCI (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Unrealized losses on available for sale debt securities:
Net (losses) gains arising during the period	$ (31,972)	$ 20,134	$ 24,987
Reclassification adjustment for gains included in net income	(230)	0	0
Total	(32,202)	20,134	24,987
Unrealized gains (losses) on derivatives (cash flow hedges)	12,189	(7,099)	(780)
Amortization related to post-retirement obligations	5,474	5,604	(2,176)
Total other comprehensive (loss) income	(14,539)	18,639	22,031
Unrealized losses on available for sale debt securities:
Net (losses) gains arising during the period	8,242	(5,190)	(6,636)
Reclassification adjustment for gains included in net income	59	0	0
Total	8,301	(5,190)	(6,636)
Unrealized gains (losses) on derivatives (cash flow hedges)	(3,142)	1,830	201
Amortization related to post-retirement obligations	(1,412)	(1,445)	561
Total other comprehensive (loss) income	3,747	(4,805)	(5,874)
Unrealized losses on available for sale debt securities:
Net (losses) gains arising during the period	(23,730)	14,944	18,351
Reclassification adjustment for gains included in net income	(171)	0	0
Total	(23,901)	14,944	18,351
Unrealized gains (losses) on derivatives (cash flow hedges)	9,047	(5,269)	(579)
Amortization related to post-retirement obligations	4,062	4,159	(1,615)
Total other comprehensive (loss) income, net of tax	$ (10,792)	$ 13,834	$ 16,157