XML 65 R38.htm IDEA: XBRL DOCUMENT v3.5.0.2
Stock-based Compensation (Details) - Restricted Stock Units (RSUs) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2016
Mar. 31, 2016
Jun. 30, 2015
Mar. 31, 2015
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Dec. 31, 2014
Restricted stock unit activity [Roll Forward]                
Unvested at beginning of period (in shares) 820,400 706,000 819,600 745,300 706,000 745,300 745,300  
Granted (in shares) 49,700   10,200   250,600 130,300    
Vested (in shares) (9,700)   (14,300)   (94,600) (56,100)    
Forfeited (in shares) (43,100)   (6,500)   (44,700) (10,500)    
Unvested at end of period (in shares) 817,300 820,400 809,000 819,600 817,300 809,000 706,000 745,300
Unvested shares expected to vest (in shares) 796,100   785,900   796,100 785,900    
Restricted stock unit activity, additional disclosures [Abstract]                
Weighted average grant date fair value, beginning of period (in dollars per share) $ 112.83 $ 111.78 $ 101.13 $ 90.43 $ 111.78 $ 90.43 $ 90.43  
Weighted average grant date fair value, granted (in dollars per share) 108.75   172.93   107.45 160.91    
Weighted average grant date fair value, vested (in dollars per share) 92.60   85.82   91.22 81.94    
Weighted average grant date fair value, forfeited (in dollars per share) 117.52   87.58   116.50 88.16    
Weighted average grant date fair value, end of period (in dollars per share) 112.58 $ 112.83 102.41 $ 101.13 112.58 102.41 $ 111.78 $ 90.43
Weighted average grant date fair value, unvested shares expected to vest (in dollars per share) $ 112.69   $ 102.62   $ 112.69 $ 102.62    
Weighted average remaining contractual life, unvested shares outstanding 1 year 11 months 29 days 2 years 2 months 14 days 2 years 1 month 24 days 2 years 4 months 5 days 1 year 11 months 27 days 2 years 1 month 24 days 2 years 10 days 2 years 4 months 16 days
Weighted average remaining contractual life, unvested shares outstanding, expected to vest 1 year 11 months 29 days   2 years 1 month 27 days   1 year 11 months 29 days 2 years 1 month 27 days    
Unamortized deferred compensation cost $ 37.0       $ 37.0      
Fair value of shares vested 0.9   $ 1.2   8.6 $ 4.6    
Share Based Compensation Arrangement By ShareBased Payment Award, Equity Instruments Other Than Options, Grants In Period, Weighted Average Grant Date Fair Value $ 5.4   $ 1.8   $ 26.9 $ 21.0