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Other Investments - Schedule of Changes in Other Investments (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Other Investments [Roll Forward] |  |  |  |
Balance, beginning of period | $ 426.0 | $ 394.1 | $ 421.6 | $ 375.2
Purchases and commitments | 36.2 | 12.1 | 46.0 | 27.1
Sales and distributions | (17.4) | (7.8) | (28.9) | (19.3)
Net realized and unrealized (losses) gains | 12.2 | (13.7) | 18.3 | 1.7
Balance, end of period | 457.0 | 384.7 | 457.0 | 384.7
Equity Securities Without Readily Determinable Fair Value [Roll Forward] |  |  |  |
Balance, beginning of period | 50.4 | 50.4 | 50.4 | 50.4
Purchases and commitments | 0.0 | 0.0 | 0.0 | 0.0
Sales and distributions | 0.0 | 0.0 | 0.0 | 0.0
Net realized and unrealized gains | 0.0 | 0.0 | 0.0 | 0.0
Balance, end of period | 50.4 | 50.4 | 50.4 | 50.4
Fair Value Measured at NAV |  |  |  |
Other Investments [Roll Forward] |  |  |  |
Balance, beginning of period | 375.6 | 343.7 | 371.2 | 324.8
Purchases and commitments | 36.2 | 12.1 | 46.0 | 27.1
Sales and distributions | (17.4) | (7.8) | (28.9) | (19.3)
Net realized and unrealized (losses) gains | 12.2 | (13.7) | 18.3 | 1.7
Balance, end of period | $ 406.6 | $ 334.3 | $ 406.6 | $ 334.3

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