Authorized Shares Of Common And Preferred Stock And Stock-Based Compensation Plans (Schedule Of Weighted Average Grant Date Fair Value Of Purchase Rights Granted Under Employee Stock Purchase Plan) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Authorized Shares Of Common And Preferred Stock And Stock-Based Compensation Plans [Abstract]
Number of shares	1,121,709	1,191,599	1,122,483
Weighted average fair value	$ 6.05	$ 5.64	$ 5.93