Consolidated balance sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Consolidated balance sheets
Accounts receivable, allowances (in dollars)	$ 200,000	$ 1,500,000
Series A Convertible preferred stock, shares authorized	10,000,000	10,000,000
Series A Convertible preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Series A Convertible preferred stock, shares issued	2,243,750	2,243,750
Series A Convertible preferred stock, shares outstanding	2,243,750	2,243,750
Series A Convertible preferred stock, aggregate liquidation preference (in dollars)	$ 8,975,000	$ 8,975,000
Common stock, shares authorized	250,000,000	250,000,000
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued	55,037,488	53,658,857
Common stock, shares outstanding	55,037,488	53,658,857