Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Future Issuance (Detail) - shares	Dec. 31, 2016	Dec. 31, 2015
Equity [Line Items]
Common stock shares reserved for future issuance	1,440,337	864,127
2008 Stock Plan
Equity [Line Items]
Common stock shares reserved for future issuance		405,893
2016 Stock Plan
Equity [Line Items]
Common stock shares reserved for future issuance	615,207
Outstanding stock options
Equity [Line Items]
Common stock shares reserved for future issuance	825,130	458,234