Share-Based Compensation (Summary Of Stock Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding Shares, Beginning balance	544,225
Granted, Shares	0	0	0
Exercised, Shares	(65,450)
Cancelled or expired, Shares	(27,750)
Outstanding Shares, Ending balance	451,025	544,225
Exercisable, Shares	408,775
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)	$ 46.09
Exercised, Weighted-Average Exercise Price (in dollars per share)	$ 38.07
Outstanding, Weighted-Average Exercise Price, Ending balance (in dollars per share)	$ 47.22	$ 46.09
Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 48.59
Outstanding, Weighted-Average Remaining Contractual Term (Years)	4 years 6 months
Exercisable, Weighted-Average Remaining Contractual Term (Years)	4 years 3 months 18 days
Outstanding, Aggregate Intrinsic Value	$ 724
Exercisable, Aggregate Intrinsic Value	$ 479