Net Income (Loss) Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net Income (Loss) Per Share
Anti-dilutive shares	1,010,304		1,508,168
Income (loss)	$ (8,718)	$ 1,151	$ (19,216)	$ 7,190
Weighted average common shares outstanding used in computing basic net income (loss) per share	107,855,000	106,417,000	107,521,000	106,152,000
Incremental shares		1,775,000		3,300,000
Weighted average common shares outstanding used in computing diluted net income (loss) per share	107,855,000	108,192,000	107,521,000	109,452,000
Net income (loss) per share:
Diluted (in dollars per share)	$ (0.08)	$ 0.01	$ (0.18)	$ 0.07
Basic (in dollars per share)	$ (0.08)	$ 0.01	$ (0.18)	$ 0.07