Investment and Equity Securities - Gross Unrealized Losses and Fair Value of Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Fair Value	$ 69,578	$ 114,437
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Unrealized Losses	931	3,602
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Fair Value	261,576	188,461
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Unrealized Losses	34,685	37,785
Available-for-sale Securities, Gross unrealized losses, Fair Value	331,154	302,898
Available-for-sale Securities, Gross unrealized losses, Unrealized Losses	35,616	41,387
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Fair Value	19,689	27,991
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Unrealized Losses	55	509
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Fair Value	31,663	22,639
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Unrealized Losses	3,550	3,809
Available-for-sale Securities, Gross unrealized losses, Fair Value	51,352	50,630
Available-for-sale Securities, Gross unrealized losses, Unrealized Losses	3,605	4,318
U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Fair Value	13,185	8,580
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Unrealized Losses	67	69
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Fair Value	26,236	13,994
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Unrealized Losses	846	979
Available-for-sale Securities, Gross unrealized losses, Fair Value	39,421	22,574
Available-for-sale Securities, Gross unrealized losses, Unrealized Losses	913	1,048
GSE - Mortgage-backed Securities and CMO's [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Fair Value	16,896	35,657
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Unrealized Losses	591	2,021
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Fair Value	97,929	77,799
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Unrealized Losses	14,123	14,043
Available-for-sale Securities, Gross unrealized losses, Fair Value	114,825	113,456
Available-for-sale Securities, Gross unrealized losses, Unrealized Losses	14,714	16,064
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Fair Value	9,128	22,828
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Unrealized Losses	83	315
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Fair Value	25,517	7,326
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Unrealized Losses	358	297
Available-for-sale Securities, Gross unrealized losses, Fair Value	34,645	30,154
Available-for-sale Securities, Gross unrealized losses, Unrealized Losses	441	612
State and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Fair Value	10,680	19,381
Available-for-sale Securities, Gross unrealized losses, Less than Twelve Months, Unrealized Losses	135	688
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Fair Value	74,839	61,359
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Unrealized Losses	15,200	18,001
Available-for-sale Securities, Gross unrealized losses, Fair Value	85,519	80,740
Available-for-sale Securities, Gross unrealized losses, Unrealized Losses	15,335	18,689
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Fair Value	5,392	5,344
Available-for-sale Securities, Gross unrealized losses, Twelve Months or More, Unrealized Losses	608	656
Available-for-sale Securities, Gross unrealized losses, Fair Value	5,392	5,344
Available-for-sale Securities, Gross unrealized losses, Unrealized Losses	$ 608	$ 656