The Company and Summary of Significant Accounting Policies (Details 1) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Numerator for basic and diluted income per share
Net income (loss)	$ 3,442,247	$ (2,294,832)	$ 7,246,065	$ (2,275,100)
Denominator for basic income per share - weighted average shares outstanding	54,520,889	60,605,140	58,849,010	61,515,979
Dilutive effect of restricted stock units	29,041		8,143
Dilutive effect of shares issuable under stock options outstanding	616,714		625,521
Denominator for diluted income per share - adjusted weighted average shares outstanding	55,166,644	60,605,140	59,482,674	61,515,979
Net income (loss) per common share:
Basic	$ 0.06	$ (0.04)	$ 0.12	$ (0.04)
Diluted	$ 0.06	$ (0.04)	$ 0.12	$ (0.04)