Redeemable Convertible Preferred Stock - Additional Information (Details)					12 Months Ended
	May. 11, 2015 shares	Apr. 27, 2015	Mar. 31, 2014 USD ($) $ / shares shares	Feb. 04, 2014 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Jan. 30, 2015 USD ($) shares	Dec. 30, 2014 USD ($)
Class Of Stock [Line Items]
Common stock, shares authorized				600,000,000	200,000,000	600,000,000
Preferred stock, shares authorized				472,083,383
Common stock, conversion basis		0.0093
Reverse stock split					one-for-107.39
Fair value of warrants | $								$ 741,828
Accretion of Series E warrant discount | $					$ 127,616	$ 313,152
Preferred Stock
Class Of Stock [Line Items]
Fair value of warrants | $					$ 5,665,000
Series E Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, price per share | $ / shares			$ 0.2189	$ 0.2189	$ 0.2189
Preferred stock, shares authorized					0	185,046,445
Issuance of preferred stock, net of issuance cost, shares			354,062	34,099,476
Warrants exercise price | $ / shares					$ 23.51
Common stock, conversion basis	0.009		1
Preferred Stock Par Or Stated Value Per Share | $ / shares					$ 0.001	$ 0.001
Liquidation preference					The Series D Convertible Preferred Stock and Series E Convertible Preferred Stock liquidation preference was equal to two times the original issue price of the Series D Convertible Preferred Stock or Series E Convertible Preferred Stock, respectively, plus any accrued but unpaid dividends whether or not declared.
Outstanding convertible preferred stock	428,237
Preferred stock cumulative dividend percentage					8.00%
Preferred stock redemption value | $					$ 0
Stock purchased by convertible note warrant holder, shares							51,681
Stock purchased by convertible note warrant holder for cash consideration | $							$ 7,196
Series E Redeemable Convertible Preferred Stock | Maximum
Class Of Stock [Line Items]
Convertible preferred stock, shares authorized				99,132,024
Series A Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares authorized					0	1,292,084
Common stock, conversion basis	0.030
Preferred Stock Par Or Stated Value Per Share | $ / shares					$ 0.001	$ 0.001
Stock holders voting percentage required for stock redemption					66.67%
Outstanding convertible preferred stock	38,973
Series B Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares authorized					0	11,919,624
Common stock, conversion basis	0.011
Preferred Stock Par Or Stated Value Per Share | $ / shares					$ 0.001	$ 0.001
Outstanding convertible preferred stock	75,835
Series C Preferred Stock
Class Of Stock [Line Items]
Preferred Stock Par Or Stated Value Per Share | $ / shares					0.001
Series D Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, price per share | $ / shares					$ 0.2189
Preferred stock, shares authorized					0	237,031,908
Warrants exercise price | $ / shares					$ 1.07
Common stock, conversion basis	0.009
Preferred Stock Par Or Stated Value Per Share | $ / shares					$ 0.001	$ 0.001
Liquidation preference					The Series D Convertible Preferred Stock and Series E Convertible Preferred Stock liquidation preference was equal to two times the original issue price of the Series D Convertible Preferred Stock or Series E Convertible Preferred Stock, respectively, plus any accrued but unpaid dividends whether or not declared.
Outstanding convertible preferred stock	1,305,984
Preferred stock cumulative dividend percentage					8.00%
Preferred stock cumulative dividends | $					$ 0
Preferred stock redemption value | $					$ 0
A B C D Stock And Series E Stock
Class Of Stock [Line Items]
Stock holders voting percentage required for stock redemption					60.00%
Series C-1
Class Of Stock [Line Items]
Common stock, conversion basis	0.014
Outstanding convertible preferred stock	191,406
Series C-2
Class Of Stock [Line Items]
Common stock, conversion basis	0.009
Outstanding convertible preferred stock	93,757
Preferred Shares Excluding Dividends
Class Of Stock [Line Items]
Outstanding convertible preferred stock	2,134,192
Series D And E Preferred Stock Cumulative Dividends
Class Of Stock [Line Items]
Outstanding convertible preferred stock	374,632
Preferred stock cumulative dividends | $						$ 7,643,378
Series E Warrants
Class Of Stock [Line Items]
Purchase of warrant exercise price per share | $ / shares				$ 0.001
Purchase price of preferred stock per Series E warrant | $ / shares			$ 0.0001	0.0001
Warrants exercise price | $ / shares			$ 0.001	$ 0.001
Financial institution warrant issued, share			118,017	11,366,486
Proceeds from Issuance of preferred stock and warrants | $			$ 77,634	$ 7,476,879
Fair value of warrants | $					$ 1,890,000
Accretion of Series E warrant discount | $					127,616	$ 313,152
Warrant Issuance Costs | $					$ 48,384
Preferred stock accreted redemption period					5 years
Series E Warrants | Maximum
Class Of Stock [Line Items]
Financial institution warrant issued, share				33,044,008
Series E Warrants | Series E Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, price per share | $ / shares					$ 0.1645
Tranche One | Series E Redeemable Convertible Preferred Stock | Maximum
Class Of Stock [Line Items]
Financial institution warrant issued, share				49,566,012
Tranche One | Series E Warrants | Maximum
Class Of Stock [Line Items]
Financial institution warrant issued, share				16,522,004