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Earnings Per Share - Schedule of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) shares in Millions, $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023
Numerator |  |  |  |
Net income (controlling interest) | $ 123.6 | $ 217.0 | $ 349.5 | $ 476.8
Income from hypothetical settlement of Redeemable non-controlling interests, net of taxes | 5.2 | 17.1 | 1.0 | 39.4
Interest expense on junior convertible securities, net of taxes | 3.4 | 3.4 | 10.1 | 10.1
Net income (controlling interest), as adjusted | $ 132.2 | $ 237.5 | $ 360.6 | $ 526.3
Denominator |  |  |  |
Average shares outstanding (basic) (in shares) | 30.1 | 34.9 | 31.4 | 35.6
Effect of dilutive instruments: |  |  |  |
Stock options and restricted stock units (in shares) | 1.7 | 1.7 | 1.9 | 1.7
Hypothetical issuance of shares to settle Redeemable non-controlling interests (in shares) | 1.5 | 5.1 | 0.2 | 3.9
Junior convertible securities (in shares) | 1.7 | 1.7 | 1.7 | 1.7
Average shares outstanding (diluted) (in shares) | 35.0 | 43.4 | 35.2 | 42.9

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