Stock-Based Compensation (Schedule Of Share-Based Compensation Stock Options Activity) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Y
Stock-Based Compensation [Abstract]
Number of Options Outstanding at beginning of period	1,133
Number of Options granted	0
Number of Options exercised	(10)
Number of Options forfeited	0
Number of Options expired	0
Number of Options Outstanding at end of period	1,123
Number of Options Exercisable at end of period	850
Weighted Average Exercise Price Outstanding at beginning of period	$ 18.01
Weighted Average Exercise Price Options granted	$ 0.00
Weighted Average Exercise Price Options exercised	$ 17.85
Weighted Average Exercise Price Options forfeited	$ 0.00
Weighted Average Exercise Price Options expired	$ 0.00
Weighted Average Exercise Price Outstanding at end of period	$ 18.01
Weighted Average Exercise Price Exercisable at end of period	$ 17.84
Weighted Average Remaining Contractual Term Outstanding at end of period, Years	4.07
Weighted Average Remaining Contractual Term Exercisable at end of period, Years	3.13
Aggregate Intrinsic Value Outstanding at end of period	$ 7,692
Aggregate Intrinsic Value Exercisable at end of period	$ 5,973