Common Equity (Common Stock And Treasury Stock Shares Activity) (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Common Stock [Member]
Common Stock And Treasury Stock [Roll Forward]
Beginning Balance	254,752,788	254,752,788	254,752,788
Ending Balance	254,752,788	254,752,788	254,752,788
Treasury Stock [Member]
Common Stock And Treasury Stock [Roll Forward]
Beginning Balance	75,623,363	76,363,763	75,512,079
Repurchases	0	0	1,468,984
Employee Stock-Based Compensation Plans	(1,377,363)	(729,073)	(610,409)
Directors' Plan	(10,865)	(11,327)	(6,891)
Ending Balance	74,235,135	75,623,363	76,363,763