Common Equity (Common Share Activity) (Details)	6 Months Ended
	Jun. 30, 2018 shares
Common Stock Oustanding [Roll Forward]
Shares outstanding, January 1, 2018 (in shares)	231,348,646
Shareowner Direct Plan issuances (in shares)	313,429
Equity-based compensation plans (in shares)	5,078
Other (in shares)	(38,423)
Shares outstanding, June 30, 2018 (in shares)	233,772,908
At The Market Offering Program [Member]
Common Stock Oustanding [Roll Forward]
At-the-market offering program (in shares)	2,144,178