Quarterly report pursuant to Section 13 or 15(d)

Debt (Narrative) (Details)

v2.4.0.6
Debt (Narrative) (Details) (USD $)
3 Months Ended 0 Months Ended 0 Months Ended 1 Months Ended 3 Months Ended 98 Months Ended 3 Months Ended
Nov. 30, 2011
Aug. 31, 2011
May 31, 2011
Nov. 30, 2011
Revolving Credit Facility [Member]
May 31, 2011
Senior Credit Facility [Member]
Feb. 23, 2011
Senior Credit Facility [Member]
Nov. 30, 2011
Senior Credit Facility - Revolver [Member]
Feb. 23, 2011
Senior Credit Facility - Revolver [Member]
Nov. 30, 2011
Senior Credit Facility - Term Loan [Member]
Feb. 23, 2011
Senior Credit Facility - Term Loan [Member]
Jun. 12, 2007
6.875% Senior Notes [Member]
Nov. 30, 2011
6.875% Senior Notes [Member]
Aug. 31, 2011
6.875% Senior Notes [Member]
May 16, 2011
2% Convertible Notes [Member]
Nov. 30, 2003
2% Convertible Notes [Member]
Nov. 30, 2011
2% Convertible Notes [Member]
Dec. 31, 2011
2% Convertible Notes [Member]
Aug. 31, 2011
2% Convertible Notes [Member]
Nov. 30, 2011
Maximum [Member]
Nov. 30, 2011
Maximum [Member]
Revolving Credit Facility [Member]
Nov. 30, 2011
Minimum [Member]
Nov. 30, 2011
Minimum [Member]
Revolving Credit Facility [Member]
Nov. 30, 2011
Class A Common Stock [Member]
2% Convertible Notes [Member]
Nov. 30, 2011
LIBOR [Member]
Feb. 23, 2011
LIBOR [Member]
Maximum [Member]
Feb. 23, 2011
LIBOR [Member]
Minimum [Member]
Feb. 23, 2011
Base Rate [Member]
Maximum [Member]
Feb. 23, 2011
Base Rate [Member]
Minimum [Member]
Feb. 23, 2011
Prior To Expansion [Member]
Senior Credit Facility [Member]
Debt Instrument [Line Items]                                                          
Maximum borrowing capacity           $ 700,000,000   $ 600,000,000                                         $ 400,000,000
Debt instrument, face amount                   100,000,000                                      
Senior Credit Facility expansion option available           300,000,000                                              
Debt instrument interest rate over variable rate                                                 2.50% 1.25% 1.25% 0.25%  
Debt interest rate, actual current spread                                               1.75%          
Debt instrument, effective percentage             2.01%   2.13%                                        
Percentage of non-use fee, annually                                       0.40%   0.20%              
Unused credit line under revolver       535,900,000                                                  
Quarterly installments payable on term loan                 1,250,000                                        
Increased quarterly installments, payable on term loan                 2,500,000                                        
Leverage ratio                                     3.75                    
Fixed charge coverage ratio                                         1.50                
Senior Notes                     250,000,000 249,456,000 249,432,000                                
Debt discount                     1,000,000                                    
Proceeds from debt, net of issuance costs                     249,000,000                                    
Senior notes issuance price percentage                     99.607%                                    
Senior notes yield percentage                     6.93%                                    
Debt instrument, maturity date                     Jun. 15, 2017       Nov. 15, 2023                            
Senior Subordinated Convertible Debentures                             150,000,000 117,591,000   117,795,000                      
Frequency of periodic interest payment, annually                               November 15 and May 15 of each year                          
Life of senior notes, years                     10                                    
Debt instrument interest rate                     6.875% 6.875%     2.00% 2.00%                          
Cash paid for repurchase                             32,200,000                            
Average price percentage of par value                                 99.30%                        
Convertible Notes converted                               200,000                          
Debt conversion converted remaining instrument amount                               117,600,000                          
Debt conversion, converted instrument, shares issued                                             5,956,619            
Debt instrument conversion rate                               $ 50.6554                          
Debt conversion principal amount                               1,000                          
Conversion price, per share                               $ 19.74                          
Minimum percentage of trading price of underlying principal amount required to receive contingent interest                           120.00%                              
Redemption price as a percentage of principal amount                               100.00%                          
Increased effective interest rate                               2.70%                          
Repurchase price as a percentage of principal amount                               100.00%                          
Notional value of interest rate swap contracts     100,000,000                                                    
Fixed interest rate of interest rate swap contracts     2.06%                                                    
Principal amount of Senior Credit Facility variable rate borrowings convertible to fixed interest rate borrowings         100,000,000                                                
Fair value of interest rate swap contracts $ 4,300,000 $ 4,600,000