Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.1
Our Portfolio - Analysis of Portfolio by Type of Obligor and Credit Quality (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]    
Equity method investments $ 458,916 $ 471,044
Receivables 918,000  
Real estate 386,000  
Investments 177,636 $ 169,793
Total 1,919,000  
Average remaining balance 10,000  
Renewable Energy Projects [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Equity method investments 437,000  
Commercial Investment Grade [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Receivables 167,000  
Real estate 364,000  
Investments 74,000  
Total 605,000  
Average remaining balance $ 6,000  
Commercial Investment Grade [Member] | Credit Concentration Risk [Member] | Debt and Real Estate Portfolio [Member]    
Financing Receivable, Recorded Investment [Line Items]    
% of Debt and real estate portfolio 41.00%  
Commercial Investment Grade [Member] | Renewable Energy Projects [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Equity method investments $ 0  
Commercial Non-Investment Grade [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Receivables 286,000  
Real estate 0  
Investments 0  
Total 286,000  
Average remaining balance $ 14,000  
Commercial Non-Investment Grade [Member] | Credit Concentration Risk [Member] | Debt and Real Estate Portfolio [Member]    
Financing Receivable, Recorded Investment [Line Items]    
% of Debt and real estate portfolio 20.00%  
Commercial Non-Investment Grade [Member] | Renewable Energy Projects [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Equity method investments $ 0  
Government [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Receivables 465,000  
Real estate 0  
Investments 104,000  
Total 569,000  
Average remaining balance $ 11,000  
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%  
Government [Member] | Renewable Energy Projects [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Equity method investments $ 0  
Subtotal, Debt and Real Estate [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Receivables 918,000  
Real estate 364,000  
Investments 178,000  
Total 1,460,000  
Average remaining balance $ 9,000  
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%  
Subtotal, Debt and Real Estate [Member] | Renewable Energy Projects [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Equity method investments $ 0  
Equity Method Investments [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Receivables 0  
Real estate 22,000  
Investments 0  
Total 459,000  
Average remaining balance 16,000  
Equity Method Investments [Member] | Renewable Energy Projects [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Equity method investments $ 437,000