Redeemable Convertible Preferred Stock - Additional Information (Details)				3 Months Ended		6 Months Ended
	May 11, 2015 $ / shares shares	Mar. 31, 2014 USD ($) $ / shares shares	Feb. 04, 2014 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2015 USD ($)	Mar. 31, 2016 $ / shares	Dec. 31, 2015 shares	Aug. 22, 2014 $ / shares
Class Of Stock [Line Items]
Common stock, shares authorized	600,000,000		600,000,000	200,000,000		200,000,000			200,000,000
Preferred stock, shares authorized			472,083,383
Reverse stock split						one-for-107.39
Accretion of Series E warrant discount | $					$ 40,146		$ 127,616
Preferred Stock
Class Of Stock [Line Items]
Fair value of warrants | $				$ 5,665,000		$ 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		$ 0.2189
Issuance of preferred stock, net of issuance cost, shares		354,062	34,099,476
Warrants exercise price | $ / shares	$ 23.51			23.51		23.51		$ 23.51		$ 0.2189
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 Stock and Series E Stock liquidation preference was equal to two times the original issue price of the Series D Stock or Series E 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%
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]
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]
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		0.001
Series D Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, price per share | $ / shares				0.2189		0.2189
Common stock, conversion basis	0.009
Preferred Stock Par Or Stated Value Per Share | $ / shares				$ 0.001		$ 0.001
Liquidation preference						The Series D Stock and Series E Stock liquidation preference was equal to two times the original issue price of the Series D Stock or Series E 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%
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
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		$ 1,890,000
Accretion of Series E warrant discount | $				$ 0	$ 40,146	0	$ 127,616
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		$ 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