Basis Of Presentation (Reconciliation Of The Numerator And Denominators Of The Basic And Diluted Net Income Per Share Computations) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Basis Of Presentation [Abstract]
Net income (loss)	$ (13,542)	$ 10,230	$ 5,757	$ 16,062
Weighted-average shares outstanding used to compute basic net income (loss) per share	56,617	58,331	57,184	54,044
Effect of dilutive securities		2,106	1,977	2,382
Weighted-average shares outstanding used to compute diluted net income (loss) per share	56,617	60,437	59,161	56,426
Basic net income (loss) per share	$ (0.24)	$ 0.18	$ 0.10	$ 0.30
Diluted net income (loss) per share	$ (0.24)	$ 0.17	$ 0.10	$ 0.28