Stockholders' Equity (Summary Of Activity Related To Stock Option Plans) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Stockholders' Equity Note [Abstract]
Shares Available for Grant, Beginning Balances	4,049,037
Options Outstanding, Number of Shares, Beginning Balances	4,572,952
Options Outstanding, Weighted-Average Exercise Price, Beginning Balances	$ 71.33
Shares Available for Grant, Granted	(244,054)
Options Outstanding, Number of Shares, Granted	244,054
Options Outstanding, Weighted-Average Exercise Price, Granted	$ 134.56
Shares Available for Grant, Exercised	0
Options Outstanding, Number of Shares, Exercised	(556,819)
Options Outstanding, Weighted-Average Exercise Price, Exercised	$ 70.30
Shares Available for Grant, Ending Balances	3,804,983
Options Outstanding, Number of Shares, Ending Balances	4,260,187
Options Outstanding, Weighted-Average Exercise Price, Ending Balances	$ 75.09
Weighted-Average Remaining Contractual Term, Ending Balances (in Years)	6 years 8 months 19 days
Aggregate Intrinsic Value, Ending Balances	$ 502,450
Options Outstanding, Number of Shares, Vested and exercisable	4,260,187
Options Outstanding, Weighted-Average Exercise Price, Vested and exercisable	$ 75.09
Weighted-Average Remaining Contractual Term, Vested and exercisable (in Years)	6 years 8 months 19 days
Aggregate Intrinsic Value, Vested and exercisable	$ 502,450