Organization and Summary of Significant Accounting Policies (Details 3) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Numerator for basic and diluted earning per share:
Net income (loss)	$ 3,814,806	$ 3,676,871	$ 3,442,247	$ 3,803,818	$ (5,901,051)	$ 1,136,285	$ (2,294,832)	$ 19,732	$ 14,737,742	$ (7,039,866)	$ (4,384,435)
Denominator:
Weighted average shares outstanding - basic									53,827,204	59,435,624	62,524,446
Dilutive effect of stock-based awards									895,581
Diluted weighted average shares outstanding									54,722,785	59,435,624	62,524,446
Anti-dilutive stock-based awards excluded									3,205,231	6,972,097	5,075,621
Net income (loss) per common share:
Basic	$ 0.07	$ 0.07	$ 0.06	$ 0.07	$ (0.11)	$ 0.02	$ (0.04)	$ 0.00	$ 0.27	$ (0.12)	$ (0.07)
Diluted	$ 0.07	$ 0.07	$ 0.06	$ 0.07	$ (0.11)	$ 0.02	$ (0.04)	$ 0.00	$ 0.27	$ (0.12)	$ (0.07)