Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders (deficit) equity (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Condensed Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders' Equity
Series A Convertible preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Series A Convertible preferred stock, shares authorized	10,000,000	4,000,000	4,000,000	4,000,000
Common stock par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	80,000,000	70,000,000	70,000,000