Stockholders' Equity (Summarized Information On Outstanding And Exercisable Options) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options	2,957,754
$1.50 - $11.48 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 1.50
Exercise Price, upper range limit	$ 11.48
Number of Options	310,542
Weighted-Average Remaining Contractual Life (Years)	2.22
Weighted-Average Exercise Price	$ 8.08
$11.57 - $18.14 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 11.57
Exercise Price, upper range limit	$ 18.14
Number of Options	311,566
Weighted-Average Remaining Contractual Life (Years)	3.25
Weighted-Average Exercise Price	$ 14.65
$19.34 - $23.48 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 19.34
Exercise Price, upper range limit	$ 23.48
Number of Options	302,259
Weighted-Average Remaining Contractual Life (Years)	5.10
Weighted-Average Exercise Price	$ 21.52
$23.78 - $27.55 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 23.78
Exercise Price, upper range limit	$ 27.55
Number of Options	300,998
Weighted-Average Remaining Contractual Life (Years)	4.62
Weighted-Average Exercise Price	$ 26.32
$28.13 - $34.75 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 28.13
Exercise Price, upper range limit	$ 34.75
Number of Options	304,110
Weighted-Average Remaining Contractual Life (Years)	5.40
Weighted-Average Exercise Price	$ 30.91
$35.36 - $53.80 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 35.36
Exercise Price, upper range limit	$ 53.80
Number of Options	314,372
Weighted-Average Remaining Contractual Life (Years)	6.55
Weighted-Average Exercise Price	$ 42.35
$58.23 - $75.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 58.23
Exercise Price, upper range limit	$ 75.00
Number of Options	308,609
Weighted-Average Remaining Contractual Life (Years)	9.07
Weighted-Average Exercise Price	$ 67.04
$80.09 - $113.25 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 80.09
Exercise Price, upper range limit	$ 113.25
Number of Options	359,849
Weighted-Average Remaining Contractual Life (Years)	9.29
Weighted-Average Exercise Price	$ 98.03
$134.91 - $237.19 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 134.91
Exercise Price, upper range limit	$ 237.19
Number of Options	298,455
Weighted-Average Remaining Contractual Life (Years)	9.09
Weighted-Average Exercise Price	$ 196.19
$242.09 - $267.99 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, lower range limit	$ 242.09
Exercise Price, upper range limit	$ 267.99
Number of Options	146,994
Weighted-Average Remaining Contractual Life (Years)	9.43
Weighted-Average Exercise Price	$ 259.98