Stockholders' Equity (Deficit) - Preferred Stock (Details) - USD ($)	1 Months Ended
	Aug. 31, 2015	Jun. 30, 2016	Dec. 31, 2015	Dec. 06, 2015
Offerings
Preferred stock, shares authorized		5,000,000	0
Preferred stock, par value per share (in dollars per share)		$ 0.001	$ 0.001
Convertible preferred stock | Series A Preferred Stock
Offerings
Preferred stock, shares authorized				599,997
Preferred stock, par value per share (in dollars per share)				$ 0.01
Convertible preferred stock | Series B Preferred Stock
Offerings
Preferred stock, shares authorized				1,202,497
Preferred stock, par value per share (in dollars per share)				$ 0.01
Convertible preferred stock | Series C Preferred Stock
Offerings
Preferred stock, shares authorized				2,073,749
Preferred stock, par value per share (in dollars per share)				$ 0.01
Convertible preferred stock | Series D Preferred Stock
Offerings
Preferred stock, shares authorized				22,995,265
Preferred stock, par value per share (in dollars per share)				$ 0.01
Convertible preferred stock | Series E Preferred Stock
Offerings
Preferred stock, shares authorized				3,192,537
Preferred stock, par value per share (in dollars per share)				$ 0.01
Convertible preferred stock | Series E Preferred Stock | Private offering
Offerings
Preferred stock, shares sold	2,711,926
Purchase price (in dollars per share)	$ 3.93
Total proceeds	$ 10,700,000
Beneficial conversion feature recognized	$ 406,783