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v3.22.2.2

Investments - Changes in Allowance for Credit Losses by Major Security Type of Investments Classified as Held-to-Maturity (Detail) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2022 USD ($) | Sep. 30, 2022 USD ($)
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Balance | $ 276 | $ 195
Provision for credit loss expense (benefit) | (21) | 60
Balance | 255 | 255
Amortized cost | 514,865 | 514,865
AAA/AA/A Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 476,260 | 476,260
Baa/BBB Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 38,593 | 38,593
B Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 12 | 12
States and Political Subdivisions [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Balance | 44 | 48
Provision for credit loss expense (benefit) |  | (4)
Balance | 44 | 44
Amortized cost | 434,938 | 434,938
States and Political Subdivisions [Member] | AAA/AA/A Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 431,963 | 431,963
States and Political Subdivisions [Member] | Baa/BBB Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 2,975 | 2,975
Corporate Bonds [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Balance | 228 | 143
Provision for credit loss expense (benefit) | (20) | 65
Balance | 208 | 208
Amortized cost | 62,390 | 62,390
Corporate Bonds [Member] | AAA/AA/A Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 26,782 | 26,782
Corporate Bonds [Member] | Baa/BBB Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 35,608 | 35,608
U.S. Agency-Based Mortgage-Backed Securities [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 3,812 | 3,812
U.S. Agency-Based Mortgage-Backed Securities [Member] | AAA/AA/A Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 3,812 | 3,812
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 13,647 | 13,647
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member] | AAA/AA/A Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 13,647 | 13,647
Asset-Backed Securities [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Balance | 4 | 4
Provision for credit loss expense (benefit) | (1) | (1)
Balance | 3 | 3
Amortized cost | 78 | 78
Asset-Backed Securities [Member] | AAA/AA/A Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 56 | 56
Asset-Backed Securities [Member] | Baa/BBB Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | 10 | 10
Asset-Backed Securities [Member] | B Ratings [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Amortized cost | $ 12 | $ 12

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- Definition Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aaa) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447 + Details
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