Net Income (Loss) Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net Income (Loss) Per Common Share [Abstract]
Net income (loss)	$ (5,480)	$ (8,804)
Denominator for basic net income (loss) per share	56,460,829	55,554,579
Denominator for diluted net income (loss) per share:	56,460,829	55,554,579
Basic net income (loss) per share	$ (0.10)	$ (0.16)
Diluted net income (loss) per share	$ (0.10)	$ (0.16)
Total number of antidilutive common stock equivalents excluded from the net income per share computation	7,500,000	5,700,000