v3.3.1.900
Stock-Based Compensation - Stock Award Activity (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Long-term performance based plans      
Stock option activity      
Total options outstanding, beginning of period (in shares) 623,100 629,300  
Total options outstanding, end of period (in shares)   623,100 629,300
Weighted-Average Exercise Price      
Total options outstanding, beginning of period (in dollars per share) $ 25.27 $ 25.27  
Total options outstanding, end of period (in dollars per share)   $ 25.27 $ 25.27
Stock options      
Stock option activity      
Total options outstanding, beginning of period (in shares) 6,669,614 6,271,058 7,908,300
Granted (in shares) 929,000 1,161,000 1,190,000
Exercised (in shares) (894,071) (697,544) (2,494,893)
Forfeited and cancelled (in shares) (811,302) (64,900) (332,349)
Total options outstanding, end of period (in shares) 5,893,241 6,669,614 6,271,058
Exercisable at end of period (in shares) 3,082,241 3,013,114 2,712,891
Weighted-Average Exercise Price      
Total options outstanding, beginning of period (in dollars per share) $ 34.02 $ 30.43 $ 27.21
Granted (in dollars per share) 51.59 47.84 38.75
Exercised (in dollars per share) 27.78 24.87 24.65
Forfeited and cancelled (in dollars per share) 29.45 32.65 27.01
Total options outstanding, end of period (in dollars per share) 38.38 34.02 30.43
Exercisable at end of period, Weighted-Average Exercise Price (in dollars per share) $ 32.61 $ 29.66 $ 28.69
Share-based compensation additional disclosures      
Tax benefits from stock options exercised $ 7.9 $ 7.2 $ 21.9
Restricted stock units      
Restricted stock unit activity      
Total restricted stock units outstanding, beginning of period (in shares) 96,768 121,877 151,683
Granted (in shares) 100,000    
Vested (in shares) (83,992) (22,877) (22,876)
Forfeited and cancelled (in shares) (55,448) (2,232) (6,930)
Total restricted stock units outstanding, end of period (in shares) 57,328 96,768 121,877
Weighted - Average Grant Date Fair Value      
Total restricted stock units outstanding, beginning of period (in dollars per share) $ 29.29 $ 29.93 $ 30.18
Granted (in dollars per share) 50.00    
Vested (in dollars per share) 45.72 33.08 33.08
Forfeited and cancelled (in dollars per share) 27.01 25.51 24.88
Total restricted stock units outstanding, end of period (in dollars per share) $ 42.31 $ 29.29 $ 29.93
Restricted stock units | Vesting Based On Performance Measurements      
Share-based compensation additional disclosures      
Expected to vest (in shares) 33,334    
Restricted stock unit activity      
Granted (in shares) 100,000    
Vested (in shares) (66,666)    
Restricted Performance Units      
Restricted stock unit activity      
Total restricted stock units outstanding, beginning of period (in shares) 55,448 57,680  
Total restricted stock units outstanding, end of period (in shares) 33,334 55,448 57,680
Weighted - Average Grant Date Fair Value      
Total restricted stock units outstanding, beginning of period (in dollars per share) $ 27.00 $ 26.94  
Total restricted stock units outstanding, end of period (in dollars per share) $ 50.00 $ 27.00 $ 26.94