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Investment Securities - Significant Unobservable Inputs (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2023
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Other long-term investments | $ 2,150.2 | $ 1,998.2
Level 3 | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Other long-term investments | $ 14.5 | $ 15.5
Level 3 | Discounted cash flow | Discount Rate | Minimum |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 11.00% | 11.00%
Level 3 | Discounted cash flow | Discount Rate | Maximum |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 12.00% | 12.00%
Kudu’s Participation Contracts |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
New and existing contracts deployed | $ 103.5 | $ 163.8
Kudu’s Participation Contracts | Level 3 | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value | $ 1,008.4 | $ 890.5
Kudu’s Participation Contracts | Level 3 | Discounted cash flow | Discount Rate | Minimum |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 17.00% | 18.00%
Kudu’s Participation Contracts | Level 3 | Discounted cash flow | Discount Rate | Maximum |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 25.00% | 25.00%
Kudu’s Participation Contracts | Level 3 | Discounted cash flow | Terminal Cash Flow Exit Multiple | Minimum |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 700.00% | 700.00%
Kudu’s Participation Contracts | Level 3 | Discounted cash flow | Terminal Cash Flow Exit Multiple | Maximum |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 2200.00% | 2200.00%
Kudu’s Participation Contracts | Level 3 | Discounted cash flow | Measurement Input, Pre-Tax Discount Rate |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 19.00% | 20.00%
Kudu’s Participation Contracts | Level 3 | Discounted cash flow | Measurement, Input, Pre-Tax Terminal Cash Flow Exit Multiple |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 1400.00% | 1300.00%
Kudu’s Participation Contracts | Level 3 | Probability weighted expected return method |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value |  | $ 69.1
PassportCard/DavidShield | Level 3 | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value | $ 150.0 | $ 150.0
PassportCard/DavidShield | Level 3 | Discounted cash flow | Discount Rate |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 24.00% | 24.00%
PassportCard/DavidShield | Level 3 | Discounted cash flow | Terminal Revenue Growth Rate |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 4.00% | 4.00%
Elementum | Level 3 | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value | $ 35.0 | $ 35.0
Elementum | Level 3 | Discounted cash flow | Discount Rate |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 22.00% | 21.00%
Elementum | Level 3 | Discounted cash flow | Terminal Revenue Growth Rate |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 4.00% | 4.00%
Preferred securities | Level 3 | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value | $ 31.4 | $ 28.2
Preferred securities | Level 3 | Discounted cash flow | Discount Rate |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Discount Rate | 9.00% | 8.00%

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