Stock-Based Compensation (Schedule of Stock Options Outstanding Expected to Vest and Exercisable) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified					12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2011 Stock Based Options [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $0.31To $0.49 [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $0.89 To $1.33 [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $1.40 To $1.65 [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $2.27 To $3.33 [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $3.71 To $5.56 [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $8.28 To $12.26 [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $12.76 To $19.07 [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $19.21 To $28.38 [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $29.36 To $43.99 [Member] years	Dec. 31, 2011 Stock Based Options [Member] Range Of Exercise Prices $44.27 To $56.60 [Member] years
Number of Options (in thousands)					7,932	43	249	170	64	448	375	2,444	1,403	1,532	1,204
Weighted Average Remaining Contractual Life (in years)					4.0	2.2	0.7	1.0	0.9	1.5	3.1	3.5	5.0	5.7	4.2
Weighted Average Exercise Price					$ 24.74	$ 0.31	$ 0.91	$ 1.62	$ 2.84	$ 4.89	$ 12.10	$ 15.30	$ 24.67	$ 36.34	$ 50.81
Aggregate Intrinsic Value (in thousands)					$ 88,887	$ 1,366	$ 7,816	$ 5,217	$ 1,871	$ 12,272	$ 7,579	$ 41,506	$ 10,678	$ 582	$ 0
Exercisable Number of Options (in thousands)					6,247	43	248	170	64	446	375	2,183	914	866	938
Exercisable Weighted Average Remaining Contractual Life (in years)					3.5	2.2	0.7	1.0	0.9	1.5	3.1	3.4	4.6	5.6	3.7
Exercisable Weighted Average Exercise Price					$ 22.54	$ 0.31	$ 0.91	$ 1.62	$ 2.84	$ 4.89	$ 12.10	$ 15.60	$ 24.56	$ 34.40	$ 51.43
Exercisable Aggregate Intrinsic Value (in thousands)					$ 81,042	$ 1,366	$ 7,782	$ 5,217	$ 1,871	$ 12,235	$ 7,576	$ 37,588	$ 7,054	$ 353	$ 0
Exercise price range, lower limit						$ 0.31	$ 0.89	$ 1.40	$ 2.27	$ 3.71	$ 8.28	$ 12.76	$ 19.21	$ 29.36	$ 44.27
Exercise price range, upper limit						$ 0.49	$ 1.33	$ 1.65	$ 3.33	$ 5.56	$ 12.26	$ 19.07	$ 28.38	$ 43.99	$ 56.60
Expected forfeitures					85
Total options outstanding	8,017	8,946	10,022	10,380	8,017