Annual report pursuant to Section 13 and 15(d)

Our Portfolio - Additional Information (Detail)

v3.6.0.2
Our Portfolio - Additional Information (Detail) - USD ($)
1 Months Ended 12 Months Ended
May 31, 2014
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]        
Financing receivables, investments, real estate and equity method investments   $ 1,635,000,000    
Deferred funding obligations   170,892,000 $ 108,499,000  
Investment securities pledged as collateral   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  
Acquisition related costs $ 2,500,000      
Acquisition completed date   Jan. 01, 2013    
Rental income   $ 11,933,000 9,107,000 $ 3,175,000
Interest income, financing receivables   48,202,000 37,404,000 23,178,000
Impairment of equity method investments   $ 0 $ 0 0
American Wind Capital Company, LLC ("AWCC") [Member]        
Financing Receivable, Recorded Investment [Line Items]        
Acquisition date   May 28, 2014    
Business combination consideration paid $ 107,000,000      
Amount of separately acquired transactions assets recognized       19,000,000
Rental income       3,200,000
Interest income, financing receivables       $ 1,500,000
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   2051    
Long-term triple net leases extended expiration dates range   2080