Stock Option And Stock Award Plans (Summary Of Stock Options Outstanding) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Number of Options
Number of Options, Outstanding, Beginning Balance	1,046,800	1,076,700	1,121,500
Number of Options, Granted	181,476	184,700	182,100
Number of Options, Forfeited and Expired	(22,581)	(34,000)	(50,300)
Number of Options, Exercised	(41,575)	(180,600)	(176,600)
Number of Options, Outstanding, Ending Balance	1,164,120	1,046,800	1,076,700
Weighted Average
Weighted Average Option Exercise Price/Share, Outstanding, Beginning Balance	$ 19.06	$ 17.81	$ 17.40
Weighted Average Option Exercise Price/Share, Granted	$ 22.41	$ 24.97	$ 19.34
Weighted Average Option Exercise Price/Share, Forfeited and Expired	$ 21.42	$ 21.10	$ 19.34
Weighted Average Option Exercise Price/Share, Exercised	$ 17.55	$ 17.32	$ 16.33
Weighted Average Option Exercise Price/Share, Outstanding, Ending Balance	$ 19.59	$ 19.06	$ 17.81
Minimum
Option Exercise Price/Share Range
Exercise Price, Outstanding, Beginning Balance	$ 14.06	$ 14.06	$ 14.06
Exercise Price, Granted	$ 19.84	$ 24.84	$ 18.51
Exercise Price, Forfeited and Expired	$ 15.8	$ 15.11	$ 15.8
Exercise Price, Exercised	$ 15.8	$ 14.27	$ 14.72
Exercise Price, Outstanding, Ending Balance	$ 14.06	$ 14.06	$ 14.06
Maximum
Option Exercise Price/Share Range
Exercise Price, Outstanding, Beginning Balance	$ 30.01	$ 19.84	$ 19.84
Exercise Price, Granted	$ 22.49	$ 30.01	$ 19.4
Exercise Price, Forfeited and Expired	$ 24.84	$ 24.84	$ 19.84
Exercise Price, Exercised	$ 19.84	$ 19.84	$ 18.12
Exercise Price, Outstanding, Ending Balance	$ 30.01	$ 30.01	$ 19.84