Common Equity (Common Share Activity) (Details)	3 Months Ended
	Mar. 31, 2018 shares
Common Stock Oustanding [Roll Forward]
Shares outstanding, January 1, 2018 (in shares)	231,348,646
Shareowner Direct Plan issuances (in shares)	166,527
Equity-based compensation plans (in shares)	5,078
Other (in shares)	(38,423)
Shares outstanding, March 31, 2018 (in shares)	231,481,828