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Common Equity (Common Share Activity) (Details) - shares | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Common Stock Oustanding [Roll Forward] |  |  |
Shares outstanding, January 1 (in shares) | 236,063,279 | 231,348,646 | 227,673,654
Common stock issued during the period, Shareowner Direct Plan (in shares) | 501,808 | 576,965 | 640,723
Common stock issued during the period, Equity-based compensation plans (in shares) | 101,478 | 5,078 | 5,185
Common stock issued during the period, Other (in shares) | (2,738) | (38,423) | (45,847)
Shares outstanding, December 31 (in shares) | 245,022,800 | 236,063,279 | 231,348,646
Equity Forward Agreements [Member] |  |  |
Common Stock Oustanding [Roll Forward] |  |  |
Common stock issued during the period (in shares) | 8,358,973 | 0 | 0
At-the-market Offering Program [Member] |  |  |
Common Stock Oustanding [Roll Forward] |  |  |
Common stock issued during the period (in shares) | 0 | 4,171,013 | 3,074,931

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