v3.26.3
Investments - Schedule of Other Investments at Fair Value (Details) - USD ($)
$ in Millions
9 Months Ended 12 Months Ended
Sep. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-Sale [Line Items]    
Fair Value $ 661.5 $ 485.7
Hedge Fund Investments    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value $ 364.2 $ 230.8
Credit Rating | Credit Concentration Risk    
Debt Securities, Available-for-Sale [Line Items]    
Concentration risk, percentage 100.00% 100.00%
Credit Rating | Credit Concentration Risk | Hedge Fund Investments    
Debt Securities, Available-for-Sale [Line Items]    
Concentration risk, percentage 55.00% 48.00%
Fixed income funds    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value $ 272.8 $ 243.0
Fixed income funds | Credit Rating | Credit Concentration Risk    
Debt Securities, Available-for-Sale [Line Items]    
Concentration risk, percentage 41.00% 50.00%
Credit    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value $ 25.7 $ 25.0
Credit | Credit Rating | Credit Concentration Risk    
Debt Securities, Available-for-Sale [Line Items]    
Concentration risk, percentage 3.00% 5.00%
Global macro    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value $ 49.7 $ 41.6
Global macro | Credit Rating | Credit Concentration Risk    
Debt Securities, Available-for-Sale [Line Items]    
Concentration risk, percentage 8.00% 9.00%
Long/short    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value $ 189.5 $ 67.4
Long/short | Credit Rating | Credit Concentration Risk    
Debt Securities, Available-for-Sale [Line Items]    
Concentration risk, percentage 29.00% 14.00%
Multi-strategy and event-driven    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value $ 99.3 $ 96.8
Multi-strategy and event-driven | Credit Rating | Credit Concentration Risk    
Debt Securities, Available-for-Sale [Line Items]    
Concentration risk, percentage 15.00% 20.00%
Private credit funds    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value $ 24.5 $ 11.9
Private credit funds | Credit Rating | Credit Concentration Risk    
Debt Securities, Available-for-Sale [Line Items]    
Concentration risk, percentage 4.00% 2.00%