v3.26.3
Geographical Breakdown of Gross Written Premium (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Gross Written Premium [Line Items]        
Amount $ 498.1 $ 311.2 $ 1,312.7 $ 820.7
Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 100.00% 100.00% 100.00% 100.00%
California        
Gross Written Premium [Line Items]        
Amount $ 101.7 $ 66.8 $ 253.9 $ 163.2
California | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 20.00% 22.00% 19.00% 20.00%
New York        
Gross Written Premium [Line Items]        
Amount $ 28.9 $ 37.7 $ 151.5 $ 99.5
New York | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 6.00% 12.00% 12.00% 12.00%
Texas        
Gross Written Premium [Line Items]        
Amount $ 99.3 $ 13.8 $ 213.5 $ 60.6
Texas | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 20.00% 4.00% 16.00% 7.00%
Florida        
Gross Written Premium [Line Items]        
Amount $ 49.8 $ 40.1 $ 149.4 $ 118.9
Florida | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 10.00% 13.00% 11.00% 15.00%
Illinois        
Gross Written Premium [Line Items]        
Amount $ 15.1 $ 9.1 $ 44.5 $ 24.0
Illinois | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 3.00% 3.00% 3.00% 3.00%
Georgia        
Gross Written Premium [Line Items]        
Amount $ 10.3 $ 9.5 $ 31.2 $ 23.0
Georgia | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 2.00% 3.00% 2.00% 3.00%
New Jersey        
Gross Written Premium [Line Items]        
Amount $ 18.6 $ 6.1 $ 34.7 $ 14.2
New Jersey | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 4.00% 2.00% 3.00% 2.00%
Colorado        
Gross Written Premium [Line Items]        
Amount $ 10.4 $ 5.9 $ 26.1 $ 16.8
Colorado | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 2.00% 2.00% 2.00% 2.00%
Massachusetts        
Gross Written Premium [Line Items]        
Amount $ 8.7 $ 7.0 $ 24.2 $ 20.4
Massachusetts | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 2.00% 2.00% 2.00% 2.00%
Pennsylvania        
Gross Written Premium [Line Items]        
Amount $ 10.5 $ 6.5 $ 24.9 $ 15.9
Pennsylvania | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 2.00% 2.00% 2.00% 2.00%
Other        
Gross Written Premium [Line Items]        
Amount $ 144.8 $ 108.7 $ 358.8 $ 264.2
Other | Geographic Concentration Risk | Gross written premium        
Gross Written Premium [Line Items]        
Concentration risk, percentage (as a percent) 29.00% 35.00% 28.00% 32.00%