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Other Investments - Schedule of Changes in Other Investments (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2024 | Mar. 31, 2023
Other Investments [Roll Forward] |  |
Balance, beginning of period | $ 480.9 | $ 421.6
Purchases and commitments | 46.8 | 9.8
Sales and distributions | (9.0) | (11.5)
Net realized and unrealized gains | 4.2 | 6.1
Balance, end of period | 522.9 | 426.0
Without Readily Determinable Fair Values |  |
Balance, beginning of period | 50.4 | 50.4
Purchases and commitments | 0.0 | 0.0
Sales and distributions | 0.0 | 0.0
Net realized and unrealized gains | 0.0 | 0.0
Balance, end of period | 50.4 | 50.4
Fair Value Measured at NAV |  |
Other Investments [Roll Forward] |  |
Balance, beginning of period | 430.5 | 371.2
Purchases and commitments | 46.8 | 9.8
Sales and distributions | (9.0) | (11.5)
Net realized and unrealized gains | 4.2 | 6.1
Balance, end of period | $ 472.5 | $ 375.6

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