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Summary Of Investments Other Than Investments In Related Parties (Detail) $ in Thousands | Dec. 31, 2022 USD ($)
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Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | $ 1,357,419 | [1]
Value | 1,303,894 |
Amount Included in the Balance Sheet | 1,303,894 |
Fixed Maturities |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 1,301,723 | [1]
Value | 1,248,198 |
Amount Included in the Balance Sheet | 1,248,198 |
Fixed Maturities | United States Government and Government Agencies and Authorities |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 352,533 | [1]
Value | 344,103 |
Amount Included in the Balance Sheet | 344,103 |
Fixed Maturities | States, Municipalities, and Political Subdivisions |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 33,471 | [1]
Value | 31,595 |
Amount Included in the Balance Sheet | 31,595 |
Fixed Maturities | Mortgage Backed And Asset Backed Securities |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 370,498 | [1]
Value | 350,180 |
Amount Included in the Balance Sheet | 350,180 |
Fixed Maturities | Public Utilities |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 39,796 | [1]
Value | 38,261 |
Amount Included in the Balance Sheet | 38,261 |
Fixed Maturities | All Other Corporate Bonds |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 505,425 | [1]
Value | 484,059 |
Amount Included in the Balance Sheet | 484,059 |
Equity securities |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 17,520 | [1]
Value | 17,520 |
Amount Included in the Balance Sheet | 17,520 |
Equity securities | Public Utilities |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 0 | [1]
Value | 0 |
Amount Included in the Balance Sheet | 0 |
Equity securities | Industrial and Miscellaneous |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 17,520 | [1]
Value | 17,520 |
Amount Included in the Balance Sheet | 17,520 |
Other long-term investments | Other Invested Assets |  |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |  |
Cost | 38,176 | [1]
Value | 38,176 |
Amount Included in the Balance Sheet | $ 38,176 |
[1] | Original cost of fixed maturities adjusted for amortization of premiums and accretion of discounts; original cost of equity securities and other long-term investments adjusted for income or loss earned on investments in accordance with equity method of accounting. All amounts are shown net of impairment losses.

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- Definition Amount of investment held by insurance company, excluding investment in related party. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 7 -Subparagraph (SX 210.12-15(Column D)) -URI https://asc.fasb.org/extlink&oid=122147990&loc=d3e611379-123010 + Details
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