v3.26.1
Segment Information - Schedule of Gross Written Premium by State (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 343.9 $ 254.2
Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 100.00% 100.00%
California    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 73.7 $ 60.4
California | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 21.40% 23.80%
Texas    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 40.7 $ 32.5
Texas | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 11.80% 12.80%
New York    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 33.3 $ 25.9
New York | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 9.70% 10.20%
Washington    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 18.1 $ 13.0
Washington | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 5.30% 5.10%
Illinois    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 14.4 $ 11.6
Illinois | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 4.20% 4.60%
New Jersey    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 13.9 $ 11.7
New Jersey | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 4.00% 4.60%
Colorado    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 12.9 $ 6.8
Colorado | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 3.80% 2.70%
Florida    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 11.2 $ 6.3
Florida | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 3.30% 2.50%
Arizona    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 9.9 $ 6.2
Arizona | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 2.90% 2.40%
Pennsylvania    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 9.5 $ 7.0
Pennsylvania | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 2.80% 2.80%
All other    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 90.3 $ 63.4
All other | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 26.10% 24.80%
US    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 327.9 $ 244.8
US | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 95.30% 96.30%
Europe and UK    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Amount $ 16.0 $ 9.4
Europe and UK | Gross written premium | Geographic Concentration Risk    
Revenues from External Customers and Long-Lived Assets [Line Items]    
% of GWP 4.70% 3.70%