Note 2 - Cash, Cash Equivalents and Short-term Investments (Detail) - Cash, Cash Equivalents and Short-Term Investments (USD $)
In Thousands, unless otherwise specified
Nov. 30, 2011
Aug. 31, 2011
Trading securities:    
Total $ 637,046 $ 674,080
Cost Basis [Member] | Bond Mutual Funds [Member]
   
Available-for-sale securities:    
Available for sale securities 20,000  
Cost Basis [Member] | Corporate Debt Securities [Member]
   
Available-for-sale securities:    
Available for sale securities 12,095 17,853
Cost Basis [Member]
   
Cash 514,815 653,979
Money market mutual funds 122,231 17,350
Certificates of deposit 205,611 211,910
Trading securities:    
Equity investments 4,998  
Total 879,750 901,092
Unrealized Gain [Member] | Bond Mutual Funds [Member]
   
Available-for-sale securities:    
Available for sale securities 36  
Unrealized Gain [Member] | Corporate Debt Securities [Member]
   
Available-for-sale securities:    
Available for sale securities 5 40
Unrealized Gain [Member]
   
Cash 0 0
Money market mutual funds 0 0
Certificates of deposit 0 0
Trading securities:    
Equity investments 0  
Total 41 40
Unrealized Loss [Member] | Bond Mutual Funds [Member]
   
Available-for-sale securities:    
Available for sale securities 0  
Unrealized Loss [Member] | Corporate Debt Securities [Member]
   
Available-for-sale securities:    
Available for sale securities (144) (116)
Unrealized Loss [Member]
   
Cash 0 0
Money market mutual funds 0 0
Certificates of deposit 0 0
Trading securities:    
Equity investments (7)  
Total (151) (116)
Recorded Basis [Member] | Bond Mutual Funds [Member]
   
Available-for-sale securities:    
Available for sale securities 20,036  
Recorded Basis [Member] | Corporate Debt Securities [Member]
   
Available-for-sale securities:    
Available for sale securities 11,956 17,777
Recorded Basis [Member]
   
Cash 514,815 653,979
Money market mutual funds 122,231 17,350
Certificates of deposit 205,611 211,910
Trading securities:    
Equity investments 4,991  
Total 879,640 901,016
Cash and Cash Equivalents [Member] | Bond Mutual Funds [Member]
   
Available-for-sale securities:    
Available for sale securities 0  
Cash and Cash Equivalents [Member] | Corporate Debt Securities [Member]
   
Available-for-sale securities:    
Available for sale securities 0 0
Cash and Cash Equivalents [Member]
   
Cash 514,815 653,979
Money market mutual funds 122,231 17,350
Certificates of deposit 0 2,751
Trading securities:    
Equity investments 0  
Total 637,046 674,080
Short-term Investments [Member] | Bond Mutual Funds [Member]
   
Available-for-sale securities:    
Available for sale securities 20,036  
Short-term Investments [Member] | Corporate Debt Securities [Member]
   
Available-for-sale securities:    
Available for sale securities 11,956 17,777
Short-term Investments [Member]
   
Cash 0 0
Money market mutual funds 0 0
Certificates of deposit 205,611 209,159
Trading securities:    
Equity investments 4,991  
Total $ 242,594 $ 226,936