Stock-Based Compensation (Summary Of Stock Option Plans Activity) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Y
Stock-Based Compensation [Abstract]
Outstanding at beginning of year, Shares	1,156
Granted, Shares
Exercised, Shares	(194)
Canceled, Shares
Outstanding at March 31, 2012, Shares	962
Options exercisable at March 31, 2012, Shares	160
Outstanding at beginning of year, Weighted - Average Exercise Price	$ 38.26
Granted, Weighted - Average Exercise Price
Exercised, Weighted - Average Exercise Price	$ 30.34
Canceled, Weighted - Average Exercise Price
Outstanding at March 31, 2012, Weighted - Average Exercise Price	$ 39.86
Options exercisable at March 31, 2012, Weighted - Average Exercise Price	$ 28.86
Outstanding at March 31, 2012, Weighted - Average Remaining Contractual Life, years	7.5
Options exercisable at March 31, 2012, Weighted - Average Remaining Contractual Life, years	0.4
Exercised, Aggregate Intrinsic Value	$ 2,666
Outstanding at March 31, 2012, Aggregate Intrinsic Value	2,973
Options exercisable at March 31, 2012, Aggregate Intrinsic Value	$ 2,264