v3.25.2
Investment Securities - Significant Unobservable Inputs (Details)
$ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2025
USD ($)
Dec. 31, 2024
USD ($)
Quantitative information for Level 3 Fair Value Measurements Assets    
Other long-term investments $ 2,307.1 $ 2,150.2
Kudu’s Participation Contracts    
Quantitative information for Level 3 Fair Value Measurements Assets    
New and existing contracts deployed 68.2 103.5
Level 3 | Recent transaction    
Quantitative information for Level 3 Fair Value Measurements Assets    
Other long-term investments 11.7 23.4
Level 3 | Discounted cash flow    
Quantitative information for Level 3 Fair Value Measurements Assets    
Other long-term investments 15.2 14.5
Level 3 | Discounted cash flow | Kudu’s Participation Contracts    
Quantitative information for Level 3 Fair Value Measurements Assets    
Fair Value 1,121.1 1,008.4
Level 3 | Discounted cash flow | PassportCard/DavidShield    
Quantitative information for Level 3 Fair Value Measurements Assets    
Fair Value 155.0 150.0
Level 3 | Discounted cash flow | Elementum    
Quantitative information for Level 3 Fair Value Measurements Assets    
Fair Value 35.0 35.0
Level 3 | Discounted cash flow | Preferred securities    
Quantitative information for Level 3 Fair Value Measurements Assets    
Fair Value 32.9 $ 31.4
Level 3 | Discounted cash flow | Private Equity Securities    
Quantitative information for Level 3 Fair Value Measurements Assets    
Fair Value $ 21.9  
Level 3 | Discount Rate | Discounted cash flow | PassportCard/DavidShield    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.24 0.24
Level 3 | Discount Rate | Discounted cash flow | Elementum    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.22 0.22
Level 3 | Discount Rate | Discounted cash flow | Preferred securities    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.08 0.09
Level 3 | Discount Rate | Discounted cash flow | Private Equity Securities    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.35  
Level 3 | Discount Rate | Discounted cash flow | Minimum    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 11.00% 11.00%
Level 3 | Discount Rate | Discounted cash flow | Minimum | Kudu’s Participation Contracts    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.17 0.17
Level 3 | Discount Rate | Discounted cash flow | Maximum    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 12.00% 12.00%
Level 3 | Discount Rate | Discounted cash flow | Maximum | Kudu’s Participation Contracts    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.25 0.25
Level 3 | Terminal Cash Flow Exit Multiple | Discounted cash flow | Minimum | Kudu’s Participation Contracts    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 7 7
Level 3 | Terminal Cash Flow Exit Multiple | Discounted cash flow | Maximum | Kudu’s Participation Contracts    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 22 22
Level 3 | Terminal Revenue Growth Rate | Discounted cash flow | PassportCard/DavidShield    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.04 0.04
Level 3 | Terminal Revenue Growth Rate | Discounted cash flow | Elementum    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.04 0.04
Level 3 | Terminal Revenue Growth Rate | Discounted cash flow | Private Equity Securities    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.04  
Level 3 | Measurement Input, Pre-Tax Discount Rate | Discounted cash flow | Kudu’s Participation Contracts    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 0.19 0.19
Level 3 | Measurement, Input, Pre-Tax Terminal Cash Flow Exit Multiple | Discounted cash flow | Kudu’s Participation Contracts    
Quantitative information for Level 3 Fair Value Measurements Assets    
Discount Rate 14 14