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Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) shares in Millions, $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021
Numerator |  |  |  |
Net Income Available to Common Shareholders - Basic | $ 52.0 | $ 49.4 | $ 518.2 | $ 377.6
Dilutive effect of Equity Units | 0.5 | 0.6 | 1.5 | 1.0
Net Income Available to Common Shareholders - Diluted | $ 52.5 | $ 50.0 | $ 519.7 | $ 378.6
Denominator |  |  |  |
Basic Average Common Shares Outstanding | 406.5 | 393.2 | 406.3 | 392.9
Dilutive potential common shares |  |  |  |
Equity Units purchase contracts | 31.3 | 35.2 | 29.4 | 21.3
Equity Units purchase contract payment balance | 3.0 | 0.0 | 3.4 | 0.0
Shares contingently issuable under employee stock plans | 0.9 | 0.9 | 1.0 | 0.7
Shares restricted under stock plans | 0.6 | 0.3 | 0.5 | 0.3
ATM forward agreements | 1.1 | 0.7 | 1.1 | 0.6
Diluted Average Common Shares | 443.4 | 430.3 | 441.7 | 415.8

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