v3.3.0.814
Summary of RSA and RSU Activity (Detail) - $ / shares
 12 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2013
Weighted-Average Remaining Contactual Term      
Outstanding at September 30, 2015 5 years    
Aggregate Intrinsic Value      
Stock price used to calculate aggregate intrinsic value $ 69.66    
Restricted Stock Awards      
Restricted stock      
Beginning balance 5,234,184    
Granted 2,145,439    
Vested (2,702,580)    
Forfeited (612,356)    
Ending balance 4,064,687 5,234,184  
Weighted-Average Grant Date Fair Value      
Beginning balance $ 40.00    
Granted 63.71 $ 49.98 $ 36.80
Vested 35.50    
Forfeited 48.32    
Ending balance $ 54.09 $ 40.00  
Weighted-Average Remaining Contactual Term      
Outstanding at September 30, 2015 1 year 6 months    
Aggregate Intrinsic Value      
Outstanding at September 30, 2015 $ 283,000,000    
Restricted Stock Units      
Restricted stock      
Beginning balance 1,866,932    
Granted 753,733    
Vested (1,005,707)    
Forfeited (172,436)    
Ending balance 1,442,522 1,866,932  
Weighted-Average Grant Date Fair Value      
Beginning balance $ 39.69    
Granted 62.88 $ 49.44 $ 36.55
Vested 35.43    
Forfeited 47.86    
Ending balance $ 53.80 $ 39.69  
Weighted-Average Remaining Contactual Term      
Outstanding at September 30, 2015 1 year 4 months 24 days    
Aggregate Intrinsic Value      
Outstanding at September 30, 2015 $ 100,000,000