Supplemental Comprehensive Income Disclosures - Related Tax Effects Allocated to Each Component of Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized holding (losses) gains on securities arising during the period	$ (131,838)	$ (29,892)	$ 19,981
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	(27,686)	(6,278)	4,196
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax	(104,152)	(23,614)	15,785
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax	2	16	70
Less: reclassification adjustment for (gains) losses on securities included in net income, Tax (Expense) Benefit	0	3	15
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	2	13	55
OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, before Tax	131,840	29,908	(19,911)
Total Unrealized (Losses) Gains on Securities, Tax (Expense) Benefit	27,686	6,281	(4,181)
OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax	104,154	23,627	(15,730)
Unrealized holding losses on derivatives arising during the period	(31,573)	(3,356)	(4,467)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	6,630	705	938
Unrealized holding gains on derivatives arising during the period, Net of Tax Amount	(24,943)	(2,651)	(3,529)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	31,573	3,356	4,467
Total unrealized gains on derivatives, Tax (Expense) Benefit	6,630	705	938
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	76	76	(537)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax	(16)	(16)	113
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax	60	(60)	424
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	(143)	(275)	155
Net (loss) gain, Tax (Expense) Benefit	(30)	(58)	32
Net gain	113	(217)	123
Total Unrealized Gains (Losses) for Postretirement Obligations, Before Tax	219	351	(692)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	46	74	(145)
Total Unrealized Gains (Losses) for Postretirement Obligations, Net of Tax	173	(277)	547
Total other comprehensive (loss) income, Pretax Amount	(163,194)	(32,913)	14,752
Other Comprehensive Income (Loss), Tax	(34,270)	(6,912)	3,098
Total other comprehensive (loss) Income	(128,924)	(26,001)	11,654
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax	(24,943)	(2,651)	(3,529)
Post-Retirement Obligation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax	60	(60)	424
Net gain	(113)
Total other comprehensive (loss) Income	$ 173	$ 277	$ (547)