v3.6.0.2
Stock-Based Compensation - ESPP (Detail) - USD ($)
$ in Thousands
1 Months Ended 12 Months Ended
Feb. 28, 2014
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Sep. 30, 2016
Stock-Based Compensation          
Stock-based compensation expense $ 4,400 $ 5,056 $ 374 $ 4,545  
Weighted-average assumptions used to estimate the fair value of ESPP shares          
Estimated dividend yield   0.00%      
ESPP          
Stock-Based Compensation          
Maximum annual increase in shares available for issuance (in shares)         800,000
Maximum annual increase in shares available for issuance, percentage of outstanding shares         1.00%
Maximum employee payroll deduction (as a percent)   100.00%      
Maximum offering period   2 years      
Period between purchases   6 months      
Price of ESPP shares as percentage of market price   85.00%      
Holding period for purchases after the first offering period   6 months      
Holding period for purchases during the first offering period   12 months      
Stock-based compensation expense   $ 3,300      
Unrecognized employee stock-based compensation   $ 3,500      
Unrecognized employee stock-based compensation, recognition period   1 year 3 months 18 days      
Weighted-average assumptions used to estimate the fair value of ESPP shares          
Expected term (years)   9 months 18 days      
Volatility (as a percent)   48.90%      
Risk-free interest rate (as a percent)   0.69%      
Estimated dividend yield   0.00%      
ESPP | Class A common stock          
Stock-Based Compensation          
Stock available for issuance (in shares)         800,000