Note 2 - Cash, Cash Equivalents and Short-term Investments (Tables)
3 Months Ended
Nov. 30, 2011
Schedule of Cash, Cash Equivalents and Short-term Investments [Table Text Block]
                            Balance Sheet Classifications  
   
 
Cost
Basis
   
Unrealized
Gain
   
Unrealized (Loss)
   
Recorded
Basis
   
Cash and Cash Equivalents
   
Short-term
Investments
 
                                     
Cash
  $ 514,815     $ —     $ —     $ 514,815     $ 514,815     $ —  
Money market mutual funds
    122,231       —       —       122,231       122,231       —  
Certificates of deposit
    205,611       —       —       205,611       —       205,611  
Available-for-sale securities:
                                               
Bond mutual funds
    20,000       36       —       20,036       —       20,036  
Corporate bonds
    12,095       5       (144 )     11,956       —       11,956  
Trading securities:
                                               
Equity investments
    4,998       —       (7 )     4,991       —       4,991  
Total
  $ 879,750     $ 41     $ (151 )   $ 879,640     $ 637,046     $ 242,594  
   
Cost
Basis
   
Unrealized
Gain
   
Unrealized (Loss)
   
Recorded
Basis
   
Cash and Cash Equivalents
   
Short-term
Investments
 
                                     
Cash
  $ 653,979     $ —     $ —     $ 653,979     $ 653,979     $ —  
Money market mutual funds
    17,350       —       —       17,350       17,350       —  
Certificates of deposit
    211,910       —       —       211,910       2,751       209,159  
Available-for-sale securities:
                                               
Corporate bonds
    17,853       40       (116 )     17,777       —       17,777  
Total
  $ 901,092     $ 40     $ (116 )   $ 901,016     $ 674,080     $ 226,936  
Realized Gain (Loss) on Investments [Table Text Block]
   
2011
   
2010
 
Proceeds
  $ 5,617     $ 25,624  
Realized gains
  $ 1     $ 73  
Realized losses
  $ —     $ —  
Schedule of Unrealized Loss on Investments [Table Text Block]
   
Less than 12 Months
 
   
Fair
Value
   
Unrealized
Loss
 
Available-for-sale:
           
Corporate bonds
    1,874       (29 )
Total
  $ 1,874     $ (29 )
Investments Classified by Contractual Maturity Date [Table Text Block]
   
Cost
Basis
   
Estimated
Fair Value
 
Due in one year or less
  $ 12,095     $ 11,956  
Due in one to two years
    —       —  
Total
  $ 12,095     $ 11,956