v3.26.1
Fair Value Measurements - Schedule of Changes in Fair Value of Securities Using Level 3 Inputs (Details) - USD ($)
$ in Thousands
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of year $ 941,944 $ 619,247
Total net gains (losses) for the period included in OCI (8,616) 4,159
Purchases 256,401 74,895
Sales 0 0
Issuances 0 0
Settlements (99,957) (42,427)
Transfers into Level 3 197,021 103,364
Transfers out of Level 3 (510,890) (3,501)
Fair value, ending year 775,546 756,727
Change in unrealized gains (losses) for the period included in earnings for assets held at period end (364) 278
Change in unrealized gains (losses) for the period included in OCI for assets held at period end (8,398) 3,482
Investments | Location, Statement of Income, Balance [Axis]: us-gaap:GainLossOnInvestments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income (438) 934
Investments | Location, Statement of Income, Balance [Axis]: us-gaap:NetInvestmentIncome    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income 81 56
Obligations of states and political subdivisions    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of year 7,409 7,426
Total net gains (losses) for the period included in OCI (4) 59
Purchases 0 0
Sales 0 0
Issuances 0 0
Settlements (64) (72)
Transfers into Level 3 2,771 0
Transfers out of Level 3 (2,705) 0
Fair value, ending year 7,409 7,530
Change in unrealized gains (losses) for the period included in earnings for assets held at period end 2 117
Change in unrealized gains (losses) for the period included in OCI for assets held at period end (4) 59
Obligations of states and political subdivisions | Location, Statement of Income, Balance [Axis]: us-gaap:GainLossOnInvestments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income 2 117
Obligations of states and political subdivisions | Location, Statement of Income, Balance [Axis]: us-gaap:NetInvestmentIncome    
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
Corporate securities    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of year 369,111 242,679
Total net gains (losses) for the period included in OCI (3,481) 3,874
Purchases 94,568 12,684
Sales 0 0
Issuances 0 0
Settlements (44,754) (9,156)
Transfers into Level 3 123,563 17,576
Transfers out of Level 3 (162,613) 0
Fair value, ending year 376,164 267,821
Change in unrealized gains (losses) for the period included in earnings for assets held at period end (315) 140
Change in unrealized gains (losses) for the period included in OCI for assets held at period end (3,745) 3,877
Corporate securities | Location, Statement of Income, Balance [Axis]: us-gaap:GainLossOnInvestments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income (302) 141
Corporate securities | Location, Statement of Income, Balance [Axis]: us-gaap:NetInvestmentIncome    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income 72 23
CLO and other ABS    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of year 565,089 367,994
Total net gains (losses) for the period included in OCI (4,615) 228
Purchases 121,369 62,211
Sales 0 0
Issuances 0 0
Settlements (55,099) (31,732)
Transfers into Level 3 70,687 85,788
Transfers out of Level 3 (345,572) (3,501)
Fair value, ending year 351,760 481,037
Change in unrealized gains (losses) for the period included in earnings for assets held at period end (51) 21
Change in unrealized gains (losses) for the period included in OCI for assets held at period end (4,134) (452)
CLO and other ABS | Location, Statement of Income, Balance [Axis]: us-gaap:GainLossOnInvestments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income (138) 21
CLO and other ABS | Location, Statement of Income, Balance [Axis]: us-gaap:NetInvestmentIncome    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income 39 28
Residential mortgage-backed securities ("RMBS")    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of year 0  
Total net gains (losses) for the period included in OCI (520)  
Purchases 40,464  
Sales 0  
Issuances 0  
Settlements (36)  
Transfers into Level 3 0  
Transfers out of Level 3 0  
Fair value, ending year 39,879  
Change in unrealized gains (losses) for the period included in earnings for assets held at period end 0  
Change in unrealized gains (losses) for the period included in OCI for assets held at period end (520)  
Residential mortgage-backed securities ("RMBS") | Location, Statement of Income, Balance [Axis]: us-gaap:GainLossOnInvestments    
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  
Residential mortgage-backed securities ("RMBS") | Location, Statement of Income, Balance [Axis]: us-gaap:NetInvestmentIncome    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income (29)  
Commercial mortgage-backed securities ("CMBS")    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of year 335 340
Total net gains (losses) for the period included in OCI 4 (2)
Purchases 0 0
Sales 0 0
Issuances 0 0
Settlements (4) (4)
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Fair value, ending year 334 339
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 5 (2)
Commercial mortgage-backed securities ("CMBS") | Location, Statement of Income, Balance [Axis]: us-gaap:GainLossOnInvestments    
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
Commercial mortgage-backed securities ("CMBS") | Location, Statement of Income, Balance [Axis]: us-gaap:NetInvestmentIncome    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income $ (1) 5
Common Stock    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of year   808
Total net gains (losses) for the period included in OCI   0
Purchases   0
Sales   0
Issuances   0
Settlements   (1,463)
Transfers into Level 3   0
Transfers out of Level 3   0
Fair value, ending year   0
Change in unrealized gains (losses) for the period included in earnings for assets held at period end   0
Change in unrealized gains (losses) for the period included in OCI for assets held at period end   0
Common Stock | Location, Statement of Income, Balance [Axis]: us-gaap:GainLossOnInvestments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Total net gains (losses) for the period included in net income   655
Common Stock | Location, Statement of Income, Balance [Axis]: us-gaap:NetInvestmentIncome    
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