Summary of Significant Accounting Policies (Details) - $ / shares	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Summary of Significant Accounting Policies
Par value of common stock	$ 0.01		$ 0.01
Expected term	4 years	4 years
Expected volatility (as a percent)	75.45%	79.76%
Risk free rate (as a percent)	1.27%	1.23%