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Fair Value Measurements - Schedule of Changes in Fair Value of Securities Using Level 3 Inputs (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2025 | Mar. 31, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | $ 619,247 |
Fair value, ending balance | 662,511 |
Investments |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 619,247 | $ 551,689
Purchases | 32,362 | 15,810
Sales | 0 | 0
Issuances | 0 | 0
Settlements | (12,975) | (4,046)
Transfers into Level 3 | 23,279 | 39,602
Transfers out of Level 3 | 0 | (46,920)
Fair value, ending balance | 662,511 | 556,762
Change in unrealized gains (losses) for the period included in earnings for assets held at period end | 131 | 409
Change in unrealized gains (losses) for the period included in OCI for assets held at period end | 533 | (60)
Investments | Net realized and unrealized gains (losses) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | 131 | 409
Investments | Net investment income earned |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | (26) | 278
Investments | Other Comprehensive Income (Loss) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in OCI | 493 | (60)
Obligations of states and political subdivisions |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 7,426 | 7,834
Purchases | 0 | 0
Sales | 0 | 0
Issuances | 0 | 0
Settlements | 0 | 0
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 | 0
Fair value, ending balance | 7,606 | 7,747
Change in unrealized gains (losses) for the period included in earnings for assets held at period end | 89 | (1)
Change in unrealized gains (losses) for the period included in OCI for assets held at period end | 91 | (86)
Obligations of states and political subdivisions | Net realized and unrealized gains (losses) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | 89 | (1)
Obligations of states and political subdivisions | Net investment income earned |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | 0 | 0
Obligations of states and political subdivisions | Other Comprehensive Income (Loss) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in OCI | 91 | (86)
Corporate securities |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 242,679 | 297,332
Purchases | 1,908 | 1,152
Sales | 0 | 0
Issuances | 0 | 0
Settlements | (5,892) | (2,870)
Transfers into Level 3 | 0 | 20,065
Transfers out of Level 3 | 0 | (28,227)
Fair value, ending balance | 240,917 | 287,496
Change in unrealized gains (losses) for the period included in earnings for assets held at period end | 101 | 140
Change in unrealized gains (losses) for the period included in OCI for assets held at period end | 2,149 | (376)
Corporate securities | Net realized and unrealized gains (losses) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | 101 | 140
Corporate securities | Net investment income earned |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | 12 | 280
Corporate securities | Other Comprehensive Income (Loss) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in OCI | 2,109 | (376)
CLO and other ABS |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 367,994 | 245,313
Purchases | 30,454 | 14,658
Sales | 0 | 0
Issuances | 0 | 0
Settlements | (7,080) | (1,173)
Transfers into Level 3 | 23,279 | 19,537
Transfers out of Level 3 | 0 | (18,693)
Fair value, ending balance | 412,802 | 260,097
Change in unrealized gains (losses) for the period included in earnings for assets held at period end | (92) | 57
Change in unrealized gains (losses) for the period included in OCI for assets held at period end | (1,710) | 399
CLO and other ABS | Net realized and unrealized gains (losses) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | (92) | 57
CLO and other ABS | Net investment income earned |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | (43) | (1)
CLO and other ABS | Other Comprehensive Income (Loss) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in OCI | (1,710) | 399
CMBS |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 340 | 356
Purchases | 0 | 0
Sales | 0 | 0
Issuances | 0 | 0
Settlements | (3) | (3)
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 | 0
Fair value, ending balance | 345 | 355
Change in unrealized gains (losses) for the period included in earnings for assets held at period end | 0 | 0
Change in unrealized gains (losses) for the period included in OCI for assets held at period end | 3 | 3
CMBS | Net realized and unrealized gains (losses) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | 0 | 0
CMBS | Net investment income earned |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | 5 | (1)
CMBS | Other Comprehensive Income (Loss) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in OCI | 3 | 3
Common Stock |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Fair value, beginning balance | 808 | 854
Purchases | 0 | 0
Sales | 0 | 0
Issuances | 0 | 0
Settlements | 0 | 0
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 | 0
Fair value, ending balance | 841 | 1,067
Change in unrealized gains (losses) for the period included in earnings for assets held at period end | 33 | 213
Change in unrealized gains (losses) for the period included in OCI for assets held at period end | 0 | 0
Common Stock | Net realized and unrealized gains (losses) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | 33 | 213
Common Stock | Net investment income earned |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in net income | 0 | 0
Common Stock | Other Comprehensive Income (Loss) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Total net gains (losses) for the period included in OCI | $ 0 | $ 0

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- Definition Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3). + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 101 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-101 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 102 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-102 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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- Definition Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3). + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 101 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-101 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(1a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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- Definition Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 101 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-101 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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