Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation Plans - Employee Stock Purchase Plan - Additional Information (Detail)

v3.19.3
Stock-Based Compensation Plans - Employee Stock Purchase Plan - Additional Information (Detail)
 9 Months Ended
Sep. 30, 2019
USD ($)
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Common stock shares available for issuance 5,272,786
Unrecognized stock-based compensation expense | $ $ 23,499,000
Unrecognized stock-based compensation expenses recognition period 3 years 6 months 21 days
Employee Stock Purchase Plan [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
ESPP offering period description The offering periods generally start on the first trading day on or after May 15 and November 15 of each year.
Length of purchase intervals 6 months
ESPP discount rate 10.00%
Common stock reserved and available for issuance 366,667
Common stock shares available for issuance 214,872
Unrecognized stock-based compensation expense | $ $ 20,000
Unrecognized stock-based compensation expenses recognition period 1 month 13 days
Employee Stock Purchase Plan - Annual Available for Issuance Share Increase [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Common stock available for future issuance authorized annual share increase 366,667
Common stock available for future issuance authorized annual percentage increase 1.00%
ESPP description The ESPP provides for annual increases in the number of shares available for issuance under the ESPP, equal to the least of (i) 366,667 shares, (ii) 1% of the outstanding shares on such date, or (iii) an amount determined by the compensation committee of the Company’s board of directors.