Net Income (Loss) Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Computation of basic and diluted net income (loss) per share
Net income (loss)	$ 2,024	$ (8,207)
Weighted average common basic shares	40,910	40,843
Effect of dilutive securities	29
Weighted average common dilutive shares	40,939	40,843
Basic and diluted net income (loss) per share	$ 0.05	$ (0.20)