Summary of Significant Accounting Policies - Net Loss per Share (Details) - shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	3,162,111	18,348,968
Convertible Preferred Stock
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders		15,988,800
Stock options
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	3,158,558	2,217,953
Restricted stock
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	3,553	142,215