Quarterly report pursuant to Section 13 or 15(d)

Our Portfolio - Additional Information (Detail)

v3.7.0.1
Our Portfolio - Additional Information (Detail)
3 Months Ended 12 Months Ended
Mar. 31, 2017
USD ($)
a
Project
Mar. 31, 2016
USD ($)
Dec. 31, 2016
USD ($)
Financing Receivable, Recorded Investment [Line Items]      
Financing receivables, investments, real estate and equity method investments $ 1,876,000,000    
Deferred funding obligations 174,601,000   $ 170,892,000
Investment securities pledged as collateral 43,000,000   41,000,000
Financing receivables on non accrual status 0   0
Loan modifications that qualify as trouble debt restructurings 0   0
Provision for credit losses $ 0   $ 0
Land purchased | a 4,000    
Number of solar projects | Project 20    
Portfolio cost $ 106,854,000 $ 7,327,000  
Amount payable upon completion of certain project related contingencies 8,000,000    
Impairment of equity method investments 0 $ 0  
Real Estate Portfolio [Member]      
Financing Receivable, Recorded Investment [Line Items]      
Real estate portfolio acquired value through equity interest in joint venture $ 21,000,000    
Joint Venture [Member]      
Financing Receivable, Recorded Investment [Line Items]      
Land purchased | a 1,100    
Lease Intangibles [Member]      
Financing Receivable, Recorded Investment [Line Items]      
Portfolio cost $ 49,000,000    
Minimum [Member]      
Financing Receivable, Recorded Investment [Line Items]      
Long-term triple net leases expiration dates range 2033    
Long-term triple net leases extended expiration dates range 2047    
Maximum [Member]      
Financing Receivable, Recorded Investment [Line Items]      
Long-term triple net leases expiration dates range 2056    
Long-term triple net leases extended expiration dates range 2080