Stock-Based Compensation (Company's Activities With Respect To Its Stock Options) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock-Based Compensation [Abstract]
Number of Shares Outstanding, Beginning Balance	2,979	2,831	3,608
Number of Shares, Granted	1,121	984	613
Number of Shares, Exercised	(780)	(776)	(1,381)
Number of Shares, Canceled	(44)	(60)	(9)
Number of Shares Outstanding, Ending Balance	3,276	2,979	2,831
Number of Shares Exercisable, Ending Balance	1,055
Number of Shares Unvested, Ending Balance	2,221
Weighted-Average Exercise Price Per Share Outstanding, Beginning Balance	$ 48.30	$ 34.06	$ 28.06
Weighted-Average Exercise Price Per Share, Granted	$ 95.51	$ 73.17	$ 47.58
Weighted-Average Exercise Price Per Share, Exercised	$ 36.34	$ 27.57	$ 24.37
Weighted-Average Exercise Price Per Share, Canceled	$ 81.21	$ 52.54	$ 37.71
Weighted-Average Exercise Price Per Share Outstanding, Ending Balance	$ 66.85	$ 48.30	$ 34.06
Weighted-Average Exercise Price Per Share Exercisable, Ending Balance	$ 41.03
Weighted-Average Exercise Price Per Share Unvested, Ending Balance	$ 79.12
Weighted-Average Remaining Contractual Life (in years) Outstanding at December 31, 2014	4 years 7 months 6 days
Weighted-Average Remaining Contractual Life (in years) Exercisable at December 31, 2014	2 years 10 months 24 days
Weighted-Average Remaining Contractual Life (in years) Unvested at December 31, 2014	5 years 4 months 24 days
Aggregate Intrinsic Value Exercisable at December 31, 2014	$ 143,883
Aggregate Intrinsic Value Outstanding at December 31, 2014	73,584
Aggregate Intrinsic Value Unvested at December 31, 2014	$ 70,300