Summary of Significant Accounting Policies - Net Loss per Share (Details) - shares	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	2,540,830	14,820,254
Convertible Preferred Stock
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders		12,598,370
Stock options
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	2,534,613	1,890,337
Restricted stock
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	6,217	331,547