Stockholders' Equity (Summary Of Activity Related To Stock Option Plans) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Available for Grant, Beginning Balances	7,013,508	2,038,502	2,591,267
Options Outstanding, Number of Shares, Beginning Balances	2,957,754	2,892,130	4,241,438
Options Outstanding, Weighted-Average Exercise Price, Beginning Balances	$ 66.59	$ 36.11	$ 22.74
Shares Available for Grant, Authorized		5,700,000
Shares Available for Grant, Granted	(1,803,798)	(724,994)	(552,765)
Options Outstanding, Number of Shares, Granted	1,803,798	724,994	552,765
Options Outstanding, Weighted-Average Exercise Price, Granted	$ 73.94	$ 154.09	$ 99.58
Options Outstanding, Number of Shares, Exercised	(188,552)	(659,370)	(1,902,073)
Options Outstanding, Weighted-Average Exercise Price, Exercised	$ 21.85	$ 29.11	$ 24.75
Shares Available for Grant, Canceled	48
Options Outstanding, Number of Shares, Canceled	(48)
Options Outstanding, Weighted-Average Exercise Price, Canceled	$ 35.95
Shares Available for Grant, Expired	(1,160,721)
Shares Available for Grant, Ending Balances	4,049,037	7,013,508	2,038,502
Options Outstanding, Number of Shares, Ending Balances	4,572,952	2,957,754	2,892,130
Options Outstanding, Weighted-Average Exercise Price, Ending Balances	$ 71.33	$ 66.59	$ 36.11
Weighted-Average Remaining Contractual Term, Ending Balances (in Years)	7 years 0 months 18 days
Aggregate Intrinsic Value, Ending Balances	$ 163,975
Options Outstanding, Number of Shares, Vested and exercisable	4,572,952
Options Outstanding, Weighted-Average Exercise Price, Vested and exercisable	$ 71.33
Weighted-Average Remaining Contractual Term, Vested and exercisable (in Years)	7 years 0 months 18 days
Aggregate Intrinsic Value, Vested and exercisable	$ 163,975