Convertible Preferred Stock (Details) (USD $)	9 Months Ended	12 Months Ended	33 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended		0 Months Ended		12 Months Ended	0 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013 Minimum	Dec. 31, 2013 Series A Preferred Stock and Series B Preferred Stock item	Dec. 31, 2013 Series A Preferred Stock and Series B Preferred Stock Minimum	Jul. 31, 2011 Series A Preferred Stock	Dec. 31, 2013 Series A Preferred Stock item	Dec. 31, 2012 Series A Preferred Stock	Aug. 13, 2012 Series A Preferred Stock Issuance under private placement	Mar. 29, 2012 Series B Preferred Stock	Dec. 31, 2013 Series B Preferred Stock item	Aug. 13, 2012 Series B Preferred Stock Issuance under private placement	Dec. 31, 2013 Series B Preferred Stock Minimum
Convertible preferred stock
Number of shares of common stock in which preferred stock is convertible										3,064,753			6,770,563
Shares issued							6,200,000				6,770,563
Issue price (in dollars per share)							$ 1.00				$ 5.50
Gross proceeds	$ 6,099,000	$ 34,992,000	$ 41,091,000				$ 6,200,000				$ 37,200,000
Issuance cost							100,000				2,200,000
Intrinsic value of the conversion option					0
Number of embedded derivatives					0
Preferred stock, conversion ratio								1
Preferred stock, conversion ratio												1
Preferred stock, conversion ratio following Reverse Stock Split								2.023	2.023	2.023			1
Price per share of shares of common stock to be sold to the public in an underwritten public offering for automatic conversion of convertible preferred stock into shares of common stock (in dollars per share)						$ 16.50
Gross proceeds on shares of common stock to be sold to the public in an underwritten public offering for automatic conversion of convertible preferred stock into shares of common stock						35,000,000
Percentage of outstanding shares of convertible preferred stock, whose holders' vote or written consent is required for conversion					70.00%
Percentage of outstanding shares of convertible preferred stock, whose holders' may elect to not receive the liquidation preference						70.00%
Amount of guaranteed dividend					0
Liquidation preference (in dollars per share)								$ 1.00				$ 5.50
Maximum liquidation distributions per share (in dollars per share)								$ 2.00				$ 11.00
Number of votes per share held by holders of common shares					1
Percentage of outstanding shares of convertible preferred stock, whose holders' affirmative vote is required for changes related to the company's activities						70.00%								60.00%
Amount of indebtedness which can be created only after obtaining at least 70% affirmative votes of the stockholders of the convertible preferred stock				$ 250,000
Number of directors entitled to be elected by the preferred stockholders								2				1