| 
            Feb 02                          
            2015                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $1,255,790              
              $34.16 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Jan 26                          
            2015                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $7,245,000              
              $72.45 p/Share              
                   
         |    
        
           
              100,000
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Jan 24                          
            2015                          
         |  
        
          
            
              SELL
             
            
                Payment of exercise price or tax liability
             
                            
         | 
        
           
              $9,456,425              
              $74.06 p/Share              
                   
         |    
        
           
              127,686
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Jan 24                          
            2015                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              -                 
                   
         |    
        
           
              244,709
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Jan 02                          
            2015                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $2,683,994              
              $73.01 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Jan 02                          
            2015                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $1,255,790              
              $34.16 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Dec 01                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $2,705,315              
              $73.59 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Dec 01                          
            2014                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $1,255,790              
              $34.16 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Nov 03                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $2,574,811              
              $70.04 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Nov 03                          
            2014                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $1,255,790              
              $34.16 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Oct 01                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $2,529,961              
              $68.82 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Oct 01                          
            2014                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $994,412              
              $27.05 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Sep 02                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $2,649,437              
              $72.07 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Sep 02                          
            2014                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $732,667              
              $19.93 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Aug 01                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $2,535,843              
              $68.98 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Aug 01                          
            2014                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $732,667              
              $19.93 p/Share              
                   
         |    
        
           
              36,762
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Jul 01                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $2,865,149              
              $72.19 p/Share              
                   
         |    
        
           
              39,689
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Jul 01                          
            2014                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $1,073,587              
              $27.05 p/Share              
                   
         |    
        
           
              39,689
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Jun 19                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $32,033,831              
              $72.97 p/Share              
                   
         |    
        
           
              439,000
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Jun 19                          
            2014                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $15,206,960              
              $34.64 p/Share              
                   
         |    
        
           
              439,000
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            May 01                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $3,092,000              
              $61.84 p/Share              
                   
         |    
        
           
              50,000
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            May 01                          
            2014                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $1,364,500              
              $27.29 p/Share              
                   
         |    
        
           
              50,000
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Apr 01                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $3,300,000              
              $66.0 p/Share              
                   
         |    
        
           
              50,000
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Apr 01                          
            2014                          
         |  
        
          
            
              BUY
             
            
                Exercise of conversion of derivative security
             
                            
         | 
        
           
              $1,364,500              
              $27.29 p/Share              
                   
         |    
        
           
              50,000
              
         | 
        
          
            
          
         |        
      
 
      
      
        | 
            Mar 03                          
            2014                          
         |  
        
          
            
              SELL
             
            
                Open market or private sale
             
                            
         | 
        
           
              $3,385,500              
              $67.71 p/Share              
                   
         |    
        
           
              50,000
              
         | 
        
          
            
          
         |