Stockholders' Equity - Summary of Reserved Shares of Common Stock for Future Issuance (Details) - shares	Jun. 30, 2017	Dec. 31, 2016	Feb. 28, 2014
Class of Stock [Line Items]
Common stock, shares reserved for future issuance	6,783,823	5,268,127
Stock Options and Restricted Stock Units
Class of Stock [Line Items]
Common stock, shares reserved for future issuance	4,856,871	3,579,694
2014 Plans
Class of Stock [Line Items]
Common stock, shares reserved for future issuance	739,579	885,328	1,785,000
Warrant To Purchase Common Stock
Class of Stock [Line Items]
Common stock, shares reserved for future issuance	509,611
Employee Stock Purchase Plan
Class of Stock [Line Items]
Common stock, shares reserved for future issuance	677,762	803,105