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, 2012 Y
Stockholders' Equity Note [Abstract]
Shares Available for Grant, Beginning Balances	7,013,508
Shares Available for Grant, Granted	(347,367)
Shares Available for Grant, Exercised	0
Shares Available for Grant, Canceled	48
Shares Available for Grant, Expired	(1,160,721)
Shares Available for Grant, Ending Balances	5,505,468
Options Outstanding, Number of Shares, Beginning Balances	2,957,754
Options Outstanding, Number of Shares, Granted	347,367
Options Outstanding, Number of Shares, Exercised	(117,016)
Options Outstanding, Number of Shares, Canceled	(48)
Options Outstanding, Number of Shares, Ending Balances	3,188,057
Options Outstanding, Number of Shares, Vested and exercisable	3,188,057
Options Outstanding, Weighted-Average Exercise Price, Beginning Balances	$ 66.59
Options Outstanding, Weighted-Average Exercise Price, Granted	$ 97.75
Options Outstanding, Weighted-Average Exercise Price, Exercised	$ 10.47
Options Outstanding, Weighted-Average Exercise Price, Canceled	$ 35.95
Options Outstanding, Weighted-Average Exercise Price, Ending Balances	$ 72.04
Options Outstanding, Weighted-Average Exercise Price, Vested and exercisable	$ 72.04
Weighted-Average Remaining Contractual Term, Ending Balances (in Years)	6.61
Weighted-Average Remaining Contractual Term, Vested and exercisable (in Years)	6.61
Aggregate Intrinsic Value, Ending Balances	$ 183,361
Aggregate Intrinsic Value, Vested and exercisable	$ 183,361