Quarterly report pursuant to Section 13 or 15(d)

Debt - Additional Information (Detail)

v2.4.0.8
Debt - Additional Information (Detail) (USD $)
3 Months Ended 3 Months Ended
Nov. 30, 2013
Nov. 30, 2013
Minimum
Nov. 30, 2013
Maximum
Nov. 30, 2013
Libor Rate
Nov. 30, 2013
Libor Rate
Minimum
Nov. 30, 2013
Libor Rate
Maximum
Nov. 30, 2013
Base Rate
Minimum
Nov. 30, 2013
Base Rate
Maximum
Nov. 30, 2013
Revolving Credit Facility
Nov. 30, 2013
Senior Credit Facility - Term Loan
Nov. 30, 2013
Senior Credit Facility - Term Loan
Starting on September 30, 2014
Nov. 30, 2013
Senior Credit Facility - Term Loan
starting on September 30, 2015
Nov. 30, 2013
Line of Credit
Senior Credit Facility - Revolver
Nov. 30, 2013
Senior Notes
5.625% Senior Notes
Apr. 16, 2012
Senior Notes
5.625% Senior Notes
Debt Instrument [Line Items]                              
Maximum borrowing capacity                 $ 600,000,000 $ 90,000,000          
Senior credit facility expansion option, available 350,000,000                            
Debt instrument, interest rate over variable rate       1.50% 1.00% 2.50% 0.00% 1.50%              
Debt Instrument, actual interest rate 1.70%                            
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage             0.15% 0.40%              
Unused credit line                         483,000,000    
Quarterly installments, payable on term loan                     1,100,000 2,300,000      
Leverage ratio     3.75                        
Interest coverage ratio   350.00%                          
Senior Notes                             $ 300,000,000
Debt instrument, interest rate                           5.625% 5.625%