Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Additional Information (Details)

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Stockholders' Equity - Additional Information (Details)
 12 Months Ended
Dec. 31, 2017
USD ($)
Vote
shares
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Class Of Stock [Line Items]      
Number of voting rights per share of common stock | Vote 1    
Preferred stock, shares authorized 10,000,000    
Preferred stock, shares issued 0    
Preferred stock, shares outstanding 0    
Dividends declared | $ $ 0 $ 0 $ 0
Stock-based compensation, unrecognized expense, nonvested granted awards | $ 9,690,000 16,057,000 12,095,000
Total weighted average fair value of stock options granted | $ 8,929,000 6,408,000 2,428,000
Other comprehensive income (loss) related to unrealized gains (losses) on foreign currency hedging and available-for-sale investments, net of tax | $ 272,000 (35,000) (37,000)
401(k) Retirement Savings Plan      
Class Of Stock [Line Items]      
Defined benefit plan, contributed by employer net of forfeitures | $ $ 557,000 $ 0 $ 0
Stock options      
Class Of Stock [Line Items]      
Rate of reduced stock-based compensation expense for estimated forfeiture 7.30% 6.90% 7.50%
Time based restricted stock units      
Class Of Stock [Line Items]      
Vesting period 4 years    
Grants of units unvested 42,028    
Time based restricted stock awards      
Class Of Stock [Line Items]      
Vesting period 4 years    
Grants of units unvested 20,789    
Performance and time based restricted stock awards      
Class Of Stock [Line Items]      
Vesting period 3 years    
Grants of units unvested 20,785    
Performance and time based restricted stock units      
Class Of Stock [Line Items]      
Vesting period 3 years    
Grants of units unvested 13,109    
Restricted stock units and restricted stock awards      
Class Of Stock [Line Items]      
Unrecognized compensation cost related to unvested employee excluding estimated forfeitures | $ $ 6,040,000    
Amount expected to recognized over weighted-average period 3 years 1 month 6 days    
Rate of reduced stock-based compensation expense for estimated forfeiture 6.00%    
Grants of units unvested 0    
Maximum | Stock options      
Class Of Stock [Line Items]      
Stock option period, expiration 10 years    
Vesting period 4 years    
Minimum | Stock options      
Class Of Stock [Line Items]      
Stock option period, expiration 7 years    
Vesting period 1 year    
2002 Plan      
Class Of Stock [Line Items]      
Stock option shares outstanding 83,133    
Number of equity awards available for grant 0    
2012 Plan      
Class Of Stock [Line Items]      
Stock option shares outstanding 317,941    
Number of equity awards available for grant 0    
2014 Plan      
Class Of Stock [Line Items]      
Stock option shares outstanding 1,532,063    
Number of equity awards available for grant 1,151,661    
Terms of shares available for issuance The number of shares available for issuance under the 2014 Plan also is increased annually on the first day of each fiscal year equal to the least of: 895,346 shares; 4% of the outstanding shares of common stock as of the last day of the Company's immediately preceding fiscal year; or such other amount as the Company's board of directors may determine.    
Common stock capital shares reserved for future issuance maximum annual increase 895,346    
Percentage on outstanding shares of common stock 4.00%    
Number of additional number of shares reserve to provision 815,594    
2012 Plan and 2002 Plan | Maximum      
Class Of Stock [Line Items]      
Stock option shares outstanding 2,328,569    
2014 ESPP Plan      
Class Of Stock [Line Items]      
Number of equity awards available for grant 592,911    
Terms of shares available for issuance The number of shares available for sale under the ESPP is increased annually on the first day of each fiscal year equal to the least of: 179,069 shares; 1.5% of the outstanding shares of the Company’s common stock on the last day of the Company’s immediately preceding fiscal year; or such other amount as may be determined by the administrator.    
Percentage on outstanding shares of common stock 1.50%    
Number of additional number of shares reserve to provision 179,069    
Maximum percentage of common stock eligible to purchase through payroll deductions for participants 15.00%    
Maximum number of shares available for participant to purchase during period 1,500    
Purchase price as percentage of stock price on offering period 85.00%    
Purchase price as percentage of stock price on exercise date 85.00%    
Potential increase of shares available for issuance 179,069