Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation Plans and Awards - Employee stock purchase plan narrative (Details)

v3.6.0.2
Stock-based Compensation Plans and Awards - Employee stock purchase plan narrative (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation expense $ 138,458 $ 111,645 $ 87,055
ESPP shares issued (in shares) 1,254,910    
ESPP      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
ESPP shares issued (in shares) 1,254,910    
ESPP | Employee stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Amounts withheld in contributions from employees $ 9,700 7,600 6,400
Stock-based compensation expense $ 3,400 $ 3,300 $ 2,100
ESPP shares issued (in shares) 1,254,910 538,398 149,378
Weighted average purchase price (in dollars per share) $ 6.76 $ 17.80 $ 23.95