v2.4.0.6
Cash, Cash Equivalents And Investments (Summary Of Cash, Cash Equivalents And Trading And Available-For-Sale Investments) (Details) (USD $)
In Thousands, unless otherwise specified
Feb. 29, 2012
Nov. 30, 2011
Cash, Cash Equivalents And Investments [Line Items]    
Cost Basis $ 354,516 $ 301,111
Unrealized Gains 329 221
Unrealized Losses (6,338) (6,377)
Fair Value 348,507 294,955
Cash [Member]
   
Cash, Cash Equivalents And Investments [Line Items]    
Cost Basis 199,407 134,890
Fair Value 199,407 134,890
Money Market Funds [Member]
   
Cash, Cash Equivalents And Investments [Line Items]    
Cost Basis 32,288 24,220
Fair Value 32,288 24,220
State And Municipal Bond Obligations [Member]
   
Cash, Cash Equivalents And Investments [Line Items]    
Cost Basis 77,955 84,193
Unrealized Gains 329 221
Unrealized Losses (5) (16)
Fair Value 78,279 84,398
Brazilian Mutual Funds [Member]
   
Cash, Cash Equivalents And Investments [Line Items]    
Cost Basis   15,346
Fair Value   15,346
Auction Rate Securities - Municipal Bonds [Member]
   
Cash, Cash Equivalents And Investments [Line Items]    
Cost Basis 27,175 27,200
Unrealized Losses (4,209) (4,269)
Fair Value 22,966 22,931
Auction Rate Securities - Student Loans [Member]
   
Cash, Cash Equivalents And Investments [Line Items]    
Cost Basis 12,500 12,700
Unrealized Losses (2,123) (2,092)
Fair Value 10,377 10,608
Corporate Bonds [Member]
   
Cash, Cash Equivalents And Investments [Line Items]    
Cost Basis 5,191 2,562
Unrealized Losses (1)  
Fair Value $ 5,190 $ 2,562