Fair Value Measurements - Carrying Value and Fair Value Measurements (Details) - Level 3 - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Carrying Value    
Fair Value, Balance Sheet Grouping    
Non-recourse debt $ 2,022,250 $ 1,881,774
Loans receivable 31,500 44,044
CMBS 4,027 2,765
Fair Value    
Fair Value, Balance Sheet Grouping    
Non-recourse debt 2,053,353 1,937,459
Loans receivable 31,500 44,044
CMBS $ 7,470 $ 8,739