XML 82 R49.htm IDEA: XBRL DOCUMENT v3.3.0.814
Stockholders' Equity - Additional Information (Detail)
9 Months Ended 18 Months Ended
Sep. 15, 2015
shares
Sep. 30, 2015
USD ($)
$ / shares
shares
Sep. 30, 2015
USD ($)
shares
Sep. 14, 2015
shares
Jul. 16, 2015
shares
Mar. 31, 2015
shares
Dec. 04, 2006
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Maximum percentage before exercise             20.00%
Number of shares available for issuance   8,800,000 8,800,000        
Employees share purchase plan, fair market value of common stock at beginning of offering period   85.00%          
Employees share purchase plan, fair market value of common stock at end of purchase period   85.00%          
Eligible employee contributions | $   $ 25,000          
Shares issued in period     312,086        
Unrecognized stock-based compensation expense | $   $ 95,700,000 $ 95,700,000        
Unrecognized stock-based compensation expense, weighted-average period for recognition   2 years 6 months          
Equity Incentive Plan [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Number of shares authorized for issuance 47,700,000       23,850,000 21,150,000  
Stock split of common stock 2            
Equity Incentive Plan [Member] | Stock options [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Weighted-average grant-date fair value per share | $ / shares   $ 25.60          
ESPP [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Number of shares authorized for issuance 6,000,000     3,000,000      
Employee stock purchase plan offerings   0 0