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Investments - Carrying Amount of Equity Method Limited Partnership Interests (Details) - USD ($) $ in Millions | Jun. 30, 2025 | Dec. 31, 2024
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Schedule of Equity Method Investments |  |
Limited partnership interests | $ 1,137.8 | $ 1,121.3
Commercial mortgage loan funds |  |
Schedule of Equity Method Investments |  |
Limited partnership interests | 591.1 | 596.0
Real estate equity funds |  |
Schedule of Equity Method Investments |  |
Limited partnership interests | 144.8 | 144.7
Private equity funds |  |
Schedule of Equity Method Investments |  |
Limited partnership interests | 110.9 | 102.2
Infrastructure equity funds |  |
Schedule of Equity Method Investments |  |
Limited partnership interests | 83.8 | 81.7
Infrastructure debt funds |  |
Schedule of Equity Method Investments |  |
Limited partnership interests | 67.2 | 69.0
Other funds |  |
Schedule of Equity Method Investments |  |
Limited partnership interests | $ 140.0 | $ 127.7

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