Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation - Additional Information (Detail)

v3.3.0.814
Stock Based Compensation - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Jan. 01, 2015
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Stock-based compensation expense   $ 1,476,000 $ 1,198,000 $ 4,792,000 $ 3,932,000
Unrecognized compensation cost related to unvested stock-based awards granted to employees under the stock option plans   12,000,000   $ 12,000,000  
Unrecognized compensation cost related to unvested stock-based awards granted to employees under the stock option plans, period for recognition       2 years 7 months 6 days  
Non-employee stock-based compensation expense   $ 32,000 $ 17,000 $ 100,000 100,000
Total intrinsic value of stock options exercised       200,000 200,000
Cash received from stock option exercises       100,000 100,000
Tax benefit realized upon exercise of option       $ 0 $ 0
2014 Equity Incentive Plan          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Remaining shares available for issuance   2,236,211   2,236,211  
2004 Employee Stock Purchase Plan          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Remaining shares available for issuance   126,837   126,837  
Additional shares authorized for issuance 100,000        
Plan participants purchased shares       154,067  
Average purchase price under 2004 Employee Stock Purchase Plan   $ 3.49   $ 3.49  
Cash proceeds       $ 500,000