Investments - Investment Securities Continuous Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Held-to-Maturity, Gross Unrealized Losses, Total	$ 18,474	$ 657
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	196,433	67,825
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	10,625	657
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	63,424
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater	7,849
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	259,857	67,825
Corporate Bonds [Member]
Marketable Securities [Line Items]
Held-to-Maturity, Gross Unrealized Losses, Total	6,657	272
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	98,590	36,443
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	4,549	272
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	30,011
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater	2,108
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	128,601	36,443
U.S. Agency-Based Mortgage-Backed Securities [Member]
Marketable Securities [Line Items]
Held-to-Maturity, Gross Unrealized Losses, Total	538	13
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	4,732	1,146
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	444	13
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	714
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater	94
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	5,446	1,146
States and Political Subdivisions [Member]
Marketable Securities [Line Items]
Held-to-Maturity, Gross Unrealized Losses, Total	9,826	240
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	87,522	23,465
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	5,319	240
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	24,980
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater	4,507
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	112,502	23,465
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Marketable Securities [Line Items]
Held-to-Maturity, Gross Unrealized Losses, Total	1,453	132
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	5,589	6,771
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	313	132
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	7,719
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater	1,140
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	$ 13,308	$ 6,771

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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