Stockholders' Equity (Deficit) - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 12 Months Ended
Oct. 13, 2015
Jul. 22, 2015
Apr. 30, 2015
Jul. 31, 2015
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Schedule Of Stockholders Equity [Line Items]              
Offering expenses         $ 3,097    
Common stock, shares issued         41,942,026 12,964,721  
Common stock, shares authorized         100,000,000 35,700,000  
Aggregate amount paid for share repurchase           $ 3,526  
Common stock warrants, issued             200,000
Common stock warrants, contractual life             10 years
Common stock warrants, exercise price             $ 10.00
Common stock warrants, exercised         100,000    
Common stock warrants, outstanding         100,000    
NT OBJECTives, Inc. [Member]              
Schedule Of Stockholders Equity [Line Items]              
Number of shares issued as part of acquisition     9,091        
Logentries [Member]              
Schedule Of Stockholders Equity [Line Items]              
Number of shares issued as part of acquisition 1,252,627            
Amended and Restated Certificate of Incorporation [Member]              
Schedule Of Stockholders Equity [Line Items]              
Common stock, shares authorized   100,000,000          
Undesignated preferred stock   10,000,000          
IPO [Member]              
Schedule Of Stockholders Equity [Line Items]              
Number of stock issued   7,417,500          
Offering price   $ 16.00          
Additional shares granted to underwriters   967,500          
Net proceeds from issuance   $ 107,300          
Underwriting discounts and commissions   8,300          
Offering expenses   $ 3,100          
Technology Crossover Ventures [Member]              
Schedule Of Stockholders Equity [Line Items]              
Offering price   $ 16.00          
Common stock, shares issued   312,500          
Net proceeds from offerings   $ 5,000   $ 5,000      
Common Stock [Member]              
Schedule Of Stockholders Equity [Line Items]              
Number of stock issued         7,730,000    
Common stock repurchased during period, shares           401,626  
Aggregate amount paid for share repurchase           $ 3,500