XML 127 R110.htm IDEA: XBRL DOCUMENT v3.6.0.2
Employee Benefit Plans (Summary of Performance Share Activity) (Details) - Performance Shares - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Performance Share Units      
Units, Outstanding, Beginning of period (in shares) 3,556,826    
Units, Granted (in shares) 767,561    
Units, Forfeited (in shares) 0    
Units, Issued (in shares) (317,329)    
Units, Cash settled (in shares) (767,561)    
Units, Outstanding, End of period (in shares) 3,239,497 3,556,826  
Units, Not Vested, End of period Units, Issued (in shares) 561,376    
Weighted-Average Grant-Date Fair Value      
Units, Outstanding, Beginning of period (in dollars per share) $ 50.11    
Units, Granted (in dollars per share) 78.62 $ 74.14 $ 72.26
Units, Forfeited (in dollars per share) 0.00    
Units, Issued (in dollars per share) 50.03    
Units, Cash settled (in dollars per share) 78.62    
Units, Outstanding, End of period (in dollars per share) 50.12 $ 50.11  
Units, Not Vested, End of period (in dollars per share) $ 52.45    
Units, Issued $ 26 $ 37 $ 13
Units, cash settled $ 60