Quarterly report pursuant to Section 13 or 15(d)

Our Portfolio - Analysis of Portfolio by Type of Obligor and Credit Quality (Detail)

v3.5.0.2
Our Portfolio - Analysis of Portfolio by Type of Obligor and Credit Quality (Detail) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2016
Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables $ 865,000  
Financing receivables held-for-sale 7,378 $ 60,376
Investments 50,291 29,017
Real estate 166,000  
Equity method investments 323,968 $ 318,769
Total 1,412,000  
Average Remaining Balance 11,000  
Commercial Investment Grade [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables 464,000  
Investments 17,000  
Real estate 166,000  
Total 647,000  
Average Remaining Balance 10,000  
Commercial Non-Investment Grade [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables 21,000  
Total 21,000  
Average Remaining Balance $ 11,000  
Credit Concentration Risk [Member] | Commercial Investment Grade [Member] | Debt and Real Estate Portfolio [Member]    
Financing Receivable, Recorded Investment [Line Items]    
% of Debt and Real Estate Portfolio 59.00%  
Credit Concentration Risk [Member] | Commercial Non-Investment Grade [Member] | Debt and Real Estate Portfolio [Member]    
Financing Receivable, Recorded Investment [Line Items]    
% of Debt and Real Estate Portfolio 2.00%  
Government [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables $ 380,000  
Financing receivables held-for-sale 7,000  
Investments 33,000  
Total 420,000  
Average Remaining Balance $ 10,000  
Government [Member] | Credit Concentration Risk [Member] | Debt and Real Estate Portfolio [Member]    
Financing Receivable, Recorded Investment [Line Items]    
% of Debt and Real Estate Portfolio 39.00%  
Subtotal, Debt and Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables $ 865,000  
Financing receivables held-for-sale 7,000  
Investments 50,000  
Real estate 166,000  
Total 1,088,000  
Average Remaining Balance $ 10,000  
Subtotal, Debt and Real Estate [Member] | Credit Concentration Risk [Member] | Debt and Real Estate Portfolio [Member]    
Financing Receivable, Recorded Investment [Line Items]    
% of Debt and Real Estate Portfolio 100.00%  
Equity Method Investments [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Equity method investments $ 324,000  
Total 324,000  
Average Remaining Balance $ 19,000