Quarterly report pursuant to Section 13 or 15(d)

Stock Plan and Stock-Based Compensation - Additional Information (Detail)

v3.19.1
Stock Plan and Stock-Based Compensation - Additional Information (Detail) - 2013 Equity Incentive Plan [Member] - shares
3 Months Ended
Jan. 01, 2019
Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Increase in shares reserved for issuance 2,378,259  
Shares available for grant   1,855,694
Employees, Directors and Consultant [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of option granted to employees   1,834,060