Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation Plans and Awards - ESPP narrative (Details)

v3.8.0.1
Stock-based Compensation Plans and Awards - ESPP narrative (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense $ 30,101 $ 32,754 $ 98,327 $ 103,841
Employee stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Percentage of eligible compensation to purchase common stock through payroll deductions (as a percent) 15.00%   15.00%  
Offering period     6 months  
Contributions from employees withheld $ 1,900 2,600 $ 8,000 6,400
Stock-based compensation expense $ 1,000 $ 900 $ 2,900 $ 2,300
Common stock issued (in shares) 739,922 643,562 1,287,687 1,254,910