Stockholders' Equity and Redeemable Convertible Preferred Stock (Details 2) - $ / shares		1 Months Ended	12 Months Ended
	Dec. 07, 2015	Jul. 21, 2015	Dec. 31, 2015	Dec. 31, 2014
Risk-free interest rate		1.69%
Minimum [Member]
Risk-free interest rate	0.57%		0.16%
Maximum [Member]
Risk-free interest rate	1.67%		1.76%
Stock Option [Member] | Minimum [Member]
Exercise price			$ 4.18	$ 25.46
Expected stock price volatility			117.20%	77.70%
Risk-free interest rate			0.74%	0.76%
Term (years)			1 year 10 months 24 days	2 years 6 months
Stock Option [Member] | Maximum [Member]
Exercise price			$ 32.87	$ 110.77
Expected stock price volatility			130.40%	90.60%
Risk-free interest rate			1.08%	1.80%
Term (years)			3 years	5 years 6 months