Consolidated Funds (Details) (USD $)
In Thousands, unless otherwise specified
Apr. 30, 2013
Number
Oct. 31, 2012
Apr. 30, 2012
Number
Schedule Of Consolidated Funds [Line Items]      
Investments $ 542,058 $ 486,933  
Other assets 52,166 89,122  
Other liabilities 72,905 91,785  
Redeemable non-controlling interests 121,252 98,765  
Number of deconsolidated sponsored funds 3   3
Consolidated Sponsored Funds [Member]
     
Schedule Of Consolidated Funds [Line Items]      
Investments 243,657 157,405  
Other assets 7,329 5,594  
Other liabilities 18,328 16,928  
Redeemable non-controlling interests 55,114 20,072  
Net interest in consolidated sponsored funds $ 177,544 $ 125,999