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Equity Plans and Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ in Millions
1 Months Ended 9 Months Ended
May 28, 2014
Jun. 30, 2017
Sep. 30, 2017
Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Stock awards with performance-based vesting criteria, outstanding     3,686,000 3,975,000
Restricted Stock Units (RSUs)        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Aggregate intrinsic value     $ 52.5  
Restricted stock unit awards outstanding     2,443,000 699,000
Employee Stock Option        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Stock awards with performance-based vesting criteria, outstanding     21,000  
Performance Based Vesting Condition        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Restricted stock unit awards outstanding     63,000  
Maximum | Employee Stock Option        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Options vesting period     4 years  
Expiration period     10 years  
Minimum | Employee Stock Option        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Options vesting period     3 years  
Expiration period     7 years  
2011 Equity Incentive Plan | Maximum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Increase in the aggregate number of shares of common stock authorized for issuance   1,600,000    
Time Based Vesting Schedule        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Total unrecognized compensation cost related to non-vested equity awards     $ 22.0  
Total unrecognized compensation cost, weighted-average vesting period     1 year 8 months 13 days  
Performance Based Vesting Schedule        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Total unrecognized compensation cost related to non-vested equity awards     $ 0.4  
2014 Employee Stock Purchase Plan        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Shares issued to employees     84,247  
Shares remaining available for future purchases     98,227  
2014 Employee Stock Purchase Plan | The commencement of the offer period (generally, the sixteenth day in February or August)        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Purchase price per share as percentage of fair market value of common stock 85.00%      
2014 Employee Stock Purchase Plan | The exercise date, which is the last day of a purchase period (generally, the fifteenth day in February or August)        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Purchase price per share as percentage of fair market value of common stock 85.00%