Market For Common Stock And Related Shareholder Matters (Price Ranges And Dividends Declared) (Details)	3 Months Ended								12 Months Ended
	Sep. 30, 2016 $ / shares	Jun. 30, 2016 $ / shares	Mar. 31, 2016 $ / shares	Dec. 31, 2015 $ / shares	Sep. 30, 2015 $ / shares	Jun. 30, 2015 $ / shares	Mar. 31, 2015 $ / shares	Dec. 31, 2014 $ / shares	Sep. 30, 2016 entity $ / shares
Class of Stock [Line Items]
Number of Common Stock Shareholders | entity									11,751
Dividends Declared	$ 0.405	$ 0.405	$ 0.395	$ 0.395	$ 0.395	$ 0.395	$ 0.385	$ 0.385
High [Member]
Class of Stock [Line Items]
Share Price	59.62	57.06	51.53	56.64	59.39	66.07	70.19	72.21	$ 59.62
Low [Member]
Class of Stock [Line Items]
Share Price	$ 53.81	$ 47.49	$ 39.79	$ 37.03	$ 48.61	$ 58.83	$ 57.73	$ 64.31	$ 53.81