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Investments - Debt Securities, Trading (Details) - USD ($) $ in Millions | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Trading |  |
Cost | $ 47.7 | $ 24.6
Unrealized gains | 1.0 | 0.0
Unrealized losses | (0.3) | (0.3)
Fair value | $ 48.4 | $ 24.3

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