Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation Plans and Awards - Schedule of shares available for grant and activity (Details)

v3.8.0.1
Stock-based Compensation Plans and Awards - Schedule of shares available for grant and activity (Details) - shares
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Shares Available for Grant      
Beginning balance (in shares) 10,409,095    
Additional shares authorized (in shares) 15,406,510    
Units granted (in shares) (2,226,443)    
ESPP shares issued (in shares) (1,287,687)    
Options forfeited (in shares) 382,769    
Options expired (in shares) 1,469,714    
Ending balance (in shares) 18,500,050 10,409,095  
Restricted stock units      
Shares Available for Grant      
Units granted (in shares) (13,627,053)    
Forfeited (in shares) 7,089,976    
Performance stock units      
Shares Available for Grant      
Units granted (in shares) 0 (1,835,250) 0
Forfeited (in shares) 665,782    
MSUs and PSUs      
Shares Available for Grant      
Forfeited (in shares) 883,169    
Equity Awards      
Shares Available for Grant      
Beginning balance (in shares) 8,344,668    
Additional shares authorized (in shares) 9,406,510    
Units granted (in shares) (2,226,443)    
ESPP shares issued (in shares) 0    
Options forfeited (in shares) 382,769    
Options expired (in shares) 1,469,714    
Ending balance (in shares) 11,723,310 8,344,668  
Equity Awards | Restricted stock units      
Shares Available for Grant      
Units granted (in shares) (13,627,053)    
Forfeited (in shares) 7,089,976    
Equity Awards | MSUs and PSUs      
Shares Available for Grant      
Forfeited (in shares) 883,169    
ESPP      
Shares Available for Grant      
Beginning balance (in shares) 2,064,427    
Additional shares authorized (in shares) 6,000,000    
Units granted (in shares) 0    
ESPP shares issued (in shares) (1,287,687)    
Options forfeited (in shares) 0    
Options expired (in shares) 0    
Ending balance (in shares) 6,776,740 2,064,427  
ESPP | Restricted stock units      
Shares Available for Grant      
Units granted (in shares) 0    
Forfeited (in shares) 0    
ESPP | MSUs and PSUs      
Shares Available for Grant      
Forfeited (in shares) 0