Stock-Based Compensation and Directors Stock Purchase Plan (Summary Of SAR Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Stock Appreciation Rights, Shares [Roll Forward]
Outstanding, Shares, Beginning Balance	1,845,863
Granted, Shares	181,556
Forfeited, Shares	(2,478)
Expired, Shares	(7,084)
Exercised, Shares	(237,279)
Outstanding, Shares, Ending Balance	1,780,578
Stock Appreciation Rights, Weighted Average Exercise Price [Roll Forward]
Outstanding, Weighted Average Exercise Price, Beginning Balance	$ 33.03
Granted, Weighted Average Exercise Price	$ 42.40
Forfeited, Weighted Average Exercise Price	$ 39.37
Expired, Weighted Average Exercise Price	$ 32.44
Exercised, Weighted Average Exercise Price	$ 33.12
Outstanding, Weighted Average Exercise Price, Ending Balance	$ 33.96
Outstanding, Weighted Average Remaining Contractual Term (in years)	3 years 8 months
Outstanding, Aggregate Intrinsic Value, Ending Balance	$ 16,966
Stock Appreciation Rights (SARs) [Member]
Stock Appreciation Rights, Weighted Average Exercise Price [Roll Forward]
Exercisable, Shares, Ending Balance	1,425,874
Exercisable, Weighted Average Exercise Price, Ending Balance	$ 32.72
Exercisable, Weighted Average Remaining Contractual Term (in years)	2 years 6 months
Exercisable, Aggregate Intrinsic Value, Ending Balance	15,356
Vested and Expected to Vest, Shares	1,763,892
Vested and Expected to Vest, Weighted Average Exercise Price, Ending Balance	$ 33.92
Vested and Expected to Vest, Weighted Average Remaining Contractual Term (in years)	3 years 8 months
Vested and Expected to Vest, Aggregate Intrinsic Value, Ending Balance	$ 16,885