Stock-Based Compensation (Summary Of Stock Options) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Stock-Based Compensation [Abstract]
Number of Options, Outstanding, Beginning balance	374
Number of Options, Exercised	(13)	(168)
Number of Options, Outstanding, Ending balance	361
Number of Options, Exercisable as of March 31, 2019	361
Weighted-Average Exercise Price, Outstanding, Beginning balance	$ 20.35
Weighted-Average Exercise Price, Exercised	21.82
Weighted-Average Exercise Price, Outstanding, Ending balance	20.29
Weighted-Average Exercise Price, Exercisable as of March 31, 2019	$ 20.29
Weighted-Average Remaining Contractual Term (Years), Outstanding	4 years 1 month 6 days
Weighted-Average Remaining Contractual Term (Years), Exercisable as of March 31, 2019	4 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding as of March 31, 2019	$ 2,150
Aggregate Intrinsic Value, Exercisable as of March 31, 2019	$ 2,150