Share-Based Compensation (Summary Of Stock Option Activity) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding Shares, Beginning balance | shares	168,000
Granted, Shares | shares	0
Exercised, Shares | shares	(62,500)
Cancelled or expired, Shares | shares	(20,000)
Outstanding Shares, Ending balance | shares	85,500
Exercisable, Shares | shares	65,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, Weighted-Average Exercise Price, Beginning balance (in dollars per share) | $ / shares	$ 48.14
Granted, Weighted-Average Exercise Price (in dollars per share) | $ / shares	0.00
Exercised, Weighted-Average Exercise Price (in dollars per share) | $ / shares	46.12
Canceled or Expired, Weighted-Average Exercise Price (in dollars per share) | $ / shares	57.10
Outstanding, Weighted-Average Exercise Price, Ending balance (in dollars per share) | $ / shares	47.52
Exercisable, Weighted-Average Exercise Price (in dollars per share) | $ / shares	$ 48.73
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, Weighted-Average Remaining Contractual Term (Years)	3 years 1 month 6 days
Exercisable, Weighted-Average Remaining Contractual Term (Years)	2 years 1 month 6 days
Outstanding, Aggregate Intrinsic Value | $	$ 1,085
Exercisable, Aggregate Intrinsic Value | $	$ 752