Consolidated Balance Sheets (Parenthetical) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Series B redeemable convertible preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Series B redeemable convertible preferred stock, shares authorized	9,357,935	9,357,935
Series B redeemable convertible preferred stock, shares issued	7,527,853	8,671,040
Series B redeemable convertible preferred stock, shares outstanding	7,527,853	8,671,040
Series B redeemable convertible preferred stock liquidation preference	$ 13,068,000	$ 14,042,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	670,000,000	445,000,000
Common stock, shares issued	5,883,503	3,983,182
Common stock, shares outstanding	5,883,503	3,983,182