Fair Value Measurements (Tables)
 12 Months Ended
Oct. 31, 2011
Fair Value Measurements Disclosure Table [Abstract]  
Summary of the assets and liabilites measured at fair value on a recurring basis and their assigned levels within the hierarchy.
 2011            
 (in thousands) Level 1 Level 2 Level 3  Other Assets Not Held at Fair Value  Total
 Cash equivalents$ 6,691$ 360,676 $ - $ -$ 367,367
               
 Investments:            
  Corporate debt securities$ -$ 4,832 $ - $ -$ 4,832
  Consolidated funds:            
  Debt securities  6,879  62,204   -   -  69,083
  Equity securities  69,279  5,155   -   -  74,434
  Separately managed            
  accounts:            
  Debt securities  4,429  6,878   -   -  11,307
  Equity securities  33,511  42   -   -  33,553
  Sponsored funds  36,128  3,713   -   -  39,841
  Collateralized loan            
  obligation entities  -  -   -   278  278
  Investments in affiliates  -  -   -   46,900  46,900
  Other investments  -  37   -   7,470  7,507
 Total Investments$ 150,226$ 82,861 $ - $ 54,648$ 287,735

 2011            
 (in thousands) Level 1 Level 2 Level 3  Other Assets Not Held at Fair Value  Total
 Other financial assets:            
  Derivative financial assets$ -$ 1,060 $ - $ -$ 1,060
  Assets of consolidated            
  collateralized loan obligation             
  entity:            
  Cash equivalents  15,829  -   -   -  15,829
  Bank loans and other             
  investments  85  456,591   5,910   -  462,586
 Total other financial assets$ 15,914$ 457,651 $ 5,910 $ -$ 479,475
               
 Financial liabilities:            
  Derivative financial liabilities$ -$ 6,654 $ - $ -$ 6,654
  Securities sold, not yet            
  purchased  -  6,270   -   -  6,270
  Liabilities of consolidated             
  collateralized loan obligation             
  entity:            
  Senior and subordinated             
  note obligations  -  -   477,699   -  477,699
 Total financial liabilities$ -$ 12,924 $ 477,699 $ -$ 490,623

               
 2010            
 (in thousands) Level 1 Level 2  Level 3  Other Assets Not Held at Fair Value Total
 Cash equivalents$ 1,291$ 90,416 $ - $ -$ 91,707

 Investments:            
  Corporate debt securities$ -$ 4,732 $ - $ -$ 4,732
  Consolidated funds:            
  Debt securities  9,372  102,213   -   -  111,585
  Equity securities  45,135  43,049   -   -  88,184
  Separately managed            
  accounts:            
  Debt securities  -  3,666   -   -  3,666
  Equity securities  27,724  968   -   -  28,692
  Sponsored funds  34,194  3,347   -   -  37,541
  Collateralized loan             
  obligation entities  -  -   -   1,391  1,391
  Investments in affiliates  -  -   -   51,111  51,111
  Other investments  -  37   -   7,470  7,507
 Total investments$ 116,425$ 158,012 $ - $ 59,972$ 334,409

 Other financial assets:            
 Derivative financial assets$ -$ 582 $ - $ -$ 582
               
 Financial liabilities:            
 Derivative financial liabilities$ -$ 3,519 $ - $ -$ 3,519
  Securities sold, not yet            
  purchased  -  731   -   -  731
 Total financial liabilities$ -$ 4,250 $ - $ -$ 4,250
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Text Block]
(in thousands) Bank loans and other investments of consolidated CLO entity  Senior and subordinated note obligations of consolidated CLO entity
       
Balance at November 1, 2010$ - $ -
Adjustment for adoption of new consolidation guidance  5,265   444,087
Net losses on investments and note obligations(1)  1,314   33,612
Purchases, sales and settlements, net (1,353)   -
Net transfers into (out of) Level 3 684   -
Balance at October 31, 2011$ 5,910 $ 477,699
Change in unrealized gains included in net income     
relating to assets and liabilities held at October 31, 2011$ 1,314 $ 33,612
       
(1) Substantially all net losses on investments and note obligations attributable to the assets and borrowings of the Company's
 consolidated CLO entity are allocated to non-controlling and other beneficial interests on the Company's Consolidated
 Statement of Income.