Redeemable Convertible Preferred Stock - Schedule of Preferred Stock (Details) - USD ($)		1 Months Ended	6 Months Ended
	May. 11, 2015	May. 31, 2015	Jun. 30, 2015
Class Of Stock [Line Items]
Conversion of preferred stock into common stock at initial public offering	$ 48,547,984		$ 57,356,049
Preferred Shares Before IPO	217,515,139
Common Shares After IPO	2,134,192		2,134,192
Carrying value including cumulative dividends	$ 57,356,049
Preferred shares before IPO including cumulative dividends		217,515,139
Common shares after IPO including dividends			2,508,824
Series A Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of preferred stock into common stock at initial public offering	$ 1,403,007		$ (1,403,007)
Preferred Shares Before IPO	1,292,084		(1,292,084)
Common Shares After IPO			38,973
Series B Preferred Stock
Class Of Stock [Line Items]
Conversion of preferred stock into common stock at initial public offering	$ 2,100,149		$ (2,100,149)
Preferred Shares Before IPO	6,789,712		(6,789,712)
Common Shares After IPO			75,835
Series C-1
Class Of Stock [Line Items]
Conversion of preferred stock into common stock at initial public offering	$ 4,569,063
Preferred Shares Before IPO	13,242,612
Common Shares After IPO			191,406
Series C-2
Class Of Stock [Line Items]
Conversion of preferred stock into common stock at initial public offering	$ 2,225,619
Preferred Shares Before IPO	9,948,331
Common Shares After IPO			93,757
Series D Preferred Stock
Class Of Stock [Line Items]
Conversion of preferred stock into common stock at initial public offering	$ 30,370,273		$ (38,163,280)
Preferred Shares Before IPO	140,252,678		(140,252,678)
Common Shares After IPO			1,305,984
Series E Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of preferred stock into common stock at initial public offering	$ 7,879,873		$ (8,894,931)
Preferred Shares Before IPO	45,989,722		(45,989,722)
Common Shares After IPO			428,237
Series D And E Preferred Stock Cumulative Dividends
Class Of Stock [Line Items]
Common Shares After IPO	374,632		374,632
Cumulative Dividends	$ 8,808,065