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Earnings Per Share - Schedule of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) shares in Millions, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Numerator |  |  |
Net income (controlling interest) | $ 672.9 | $ 1,145.9 | $ 565.7
Income from hypothetical settlement of Redeemable non-controlling interests, net of tax | 49.0 | 82.9 | 0.0
Interest expense on junior convertible securities, net of taxes | 13.4 | 14.0 | 18.5
Net income (controlling interest), as adjusted | $ 735.3 | $ 1,242.8 | $ 584.2
Denominator |  |  |
Average shares outstanding (basic) (in shares) | 35.1 | 38.5 | 41.5
Effect of dilutive instruments: |  |  |
Stock options and restricted stock units (in shares) | 1.7 | 1.3 | 1.2
Hypothetical issuance of shares to settle Redeemable non-controlling interests (in shares) | 3.7 | 7.4 | 0.0
Junior convertible securities (in shares) | 1.7 | 1.8 | 2.1
Average shares outstanding (diluted) (in shares) | 42.2 | 49.0 | 44.8

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