Quarterly report pursuant to Section 13 or 15(d)

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

v3.5.0.2
Stock-Based Compensation Plans - Employee Stock Purchase Plan - Additional Information (Detail)
 6 Months Ended
Jun. 30, 2016
USD ($)
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Common stock shares available for issuance 4,383,914
Unrecognized stock-based compensation expense | $ $ 21,158,000
Unrecognized stock-based compensation expenses recognition period 3 years 4 months 6 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. The first offering period began on May 15, 2014.
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 289,244
Unrecognized stock-based compensation expense | $ $ 81,000
Unrecognized stock-based compensation expenses recognition period 4 months 17 days