v3.26.1
Segment Reporting Segment Net Income Before Taxes (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Segment Reporting [Line Items]                
NumberOfReportableSegmentsDisclosedByDefinitionFlag     single          
Premiums Written, Gross $ 163.4 $ 203.3 $ 344.2 $ 415.4        
Premiums Written, Net 162.0 201.5 341.4 411.8        
Net premiums earned 174.1 198.3 355.0 381.3        
Net investment income 27.4 27.1 55.7 59.2        
Net realized and unrealized gains on investments 18.7 20.9 17.0 8.1        
Other income     0.1 0.3        
Revenues 220.2 246.3 427.8 448.9        
Losses and loss adjustment expenses 122.3 140.1 251.5 260.8        
Commission expense 22.2 26.1 45.9 49.1        
Labor and Related Expense 22.9 23.9 47.9 51.5        
Information Technology and Data Processing 2.9 2.8 5.6 5.8        
Professional Fees 5.0 5.4 10.0 10.2        
Depreciation and amortization expenses 3.3 3.3 6.3 6.7        
Other General and Administrative Expense 2.5 2.2 5.0 4.3        
AO and other expense allocations, other underwriting expense (8.5) (9.3) (17.0) (19.9)        
Premium taxes and assessments 6.9 7.6 14.0 15.1        
Policyholder Dividends, Expense 0.8 2.2 1.9 5.0        
Bad debt expense 3.9 5.0 6.9 7.3        
Interest and financing expenses 1.3   2.4 0.1        
Total expenses 185.5 209.3 380.4 396.0        
Net Income before income taxes 34.7 37.0 47.4 52.9        
Income tax expense 5.6 7.3 8.2 10.4        
Net income $ 29.1 $ 29.7 $ 39.2 $ 42.5        
Combined Ratio 105.80% 105.60% 106.40% 103.90%        
Stockholders’ equity $ 858.8 $ 1,083.1 $ 858.8 $ 1,083.1 $ 866.5 $ 955.7 $ 1,075.7 $ 1,068.7
Deferred Reinsurance Gain LPT Agreement 85.3 90.7 85.3 90.7   88.0    
Accumulated other comprehensive (loss) income, net of tax 12.2 53.2 12.2 53.2   $ (7.3)    
Adjusted Stockholder's Equity 956.3 1,227.0 956.3 1,227.0        
Insurance Operations                
Segment Reporting [Line Items]                
Premiums Written, Gross 163.4 203.3 344.2 415.4        
Premiums Written, Net 162.0 201.5 341.4 411.8        
Net premiums earned 174.1 198.3 355.0 381.3        
Net investment income 27.4 27.1 55.7 59.2        
Net realized and unrealized gains on investments 18.7 20.9 17.0 8.1        
Other income 0.0 0.0 0.1 0.3        
Revenues 220.2 246.3 427.8 448.9        
Losses and loss adjustment expenses 122.3 140.1 251.5 260.8        
Commission expense 22.2 26.1 45.9 49.1        
Labor and Related Expense 22.9 23.9 47.9 51.5        
Information Technology and Data Processing 2.9 2.8 5.6 5.8        
Professional Fees 5.0 5.4 10.0 10.2        
Depreciation and amortization expenses 3.3 3.3 6.3 6.7        
Other General and Administrative Expense 2.5 2.2 5.0 4.3        
AO and other expense allocations, other underwriting expense (8.5) (9.3) (17.0) (19.9)        
Premium taxes and assessments 6.9 7.6 14.0 15.1        
Policyholder Dividends, Expense 0.8 2.2 1.9 5.0        
Bad debt expense 3.9 5.0 6.9 7.3        
Interest and financing expenses 1.3 0.0 2.4 0.1        
Total expenses 185.5 209.3 380.4 396.0        
Net Income before income taxes 34.7 37.0 47.4 52.9        
Income tax expense 5.6 7.3 8.2 10.4        
Net income $ 29.1 $ 29.7 $ 39.2 $ 42.5        
Combined Ratio 105.80% 105.60% 106.40% 103.90%        
Stockholders’ equity $ 858.8 $ 1,083.1 $ 858.8 $ 1,083.1        
Deferred Reinsurance Gain LPT Agreement 85.3 90.7 85.3 90.7        
Accumulated other comprehensive (loss) income, net of tax 12.2 53.2 12.2 53.2        
Adjusted Stockholder's Equity $ 956.3 $ 1,227.0 $ 956.3 $ 1,227.0