Variable Interest Entities Investments in VIEs That Are Consolidated (Details) (USD $)
12 Months Ended
Oct. 31, 2011
Oct. 31, 2010
Investments In Variable Interest Entities That Are Consolidated Details [Abstract]    
Unpaid principal balance (Total CLO bank loan investments) $ 474,515,000  
Excess unpaid principal balance over fair value (Total CLO bank loan investments) (17,820,000)  
Fair Value (Total CLO bank loan investments) 456,695,000  
Unpaid principal balance (90 days or more past due) 1,192,000  
Excess unpaid principal balance over fair value (90 days or more past due) (617,000)  
Fair Value (90 days or more past due) 575,000  
Unpaid principal balance (Senior and subordinated note obligations) 500,066,000  
Excess unpaid principal balance over fair value (Senior and subordinated note obligations) (22,367,000)  
Senior and subordinated note obligations 477,699,000 0
Clo Bank Loan Investments And Note Obligations Activity    
Net gains (losses) resulting from change in fair value of the CLO entitys investments 4,600,000  
Net loss resulting from an increase in the fair value of the CLOs note obligations. 33,600,000  
Minimum variable interest rate on the note obligations held by the CLO entitys (as a percent) 0.21%  
Maximum variable interest rate on the note obligations held by the CLO entitys (as a percent) 1.50%  
Maturity date Apr. 20, 2019  
Assets of consolidated collateralized loan obligation entity:    
Cash and cash equivalents 16,521,000 0
Bank loans and other investments 462,586,000 0
Other assets 2,715,000 0
Liabilities of consolidated collateralized loan obligation entity:    
Senior and subordinated note obligations 477,699,000 0
Other liabilities 5,193,000 0
Appropriated deficit (3,867,000) 0
Total net interest in consolidated collateralized loan obligation entity 2,797,000  
The CLOs net losses recorded in the Company's Consolidated Statement of Income 31,000,000  
The third-party note holders of the CLO entities net loss recorded during the period included in net income attributable to non-controlling and other beneficial interests 34,500,000  
Other Entities VIEs That Are Consolidated    
Variable interest entity ownership percentage owned by the Company's subsidiary 60.00%  
Carrying value of variable interest entity's assets (Parametric Risk Advisors) 4,900,000 3,800,000
Carrying value of variable interest entity's current liabilities (Parametric Risk Advisors) $ 2,500,000 $ 1,700,000