Quarterly report pursuant to Section 13 or 15(d)

Financing Receivables and Investments - Analysis of Financing Receivables and Investments by Type of Obligor and Credit Quality (Detail)

v2.4.0.8
Financing Receivables and Investments - Analysis of Financing Receivables and Investments by Type of Obligor and Credit Quality (Detail) (USD $)
 3 Months Ended
Mar. 31, 2014
Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables $ 395,500,000  
Investments 91,277,000 91,964,000
Total 486,800,000  
% of Total Portfolio 100.00%  
Average Remaining Balance 13,800,000  
Federal [Member]
    
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables 228,500,000  
Investments     
Total 228,500,000  
% of Total Portfolio 46.90%  
Average Remaining Balance 9,800,000  
State, Local, Institutions [Member]
    
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables 73,500,000  
Investments     
Total 73,500,000  
% of Total Portfolio 15.10%  
Average Remaining Balance 24,500,000  
Commercial Externally Rated [Member]
    
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables     
Investments 76,200,000  
Total 76,200,000  
% of Total Portfolio 15.70%  
Average Remaining Balance 25,400,000  
Commercial Rated Internally [Member]
    
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables 92,700,000  
Investments     
Total 92,700,000  
% of Total Portfolio 19.00%  
Average Remaining Balance 18,500,000  
Commercial Other [Member]
    
Financing Receivable, Recorded Investment [Line Items]    
Financing receivables 800,000  
Investments 15,100,000  
Total 15,900,000  
% of Total Portfolio 3.30%  
Average Remaining Balance $ 15,100,000