Investments - Schedule of Loan Activity (Details)
$ in Thousands
9 Months Ended
Sep. 30, 2019
USD ($)
Property
Number of Properties  
Ending balance (in properties) | Property 1,666
Loans Receivable  
Beginning Balance $ 44,742
Acquisitions 0
Dispositions 0
Principal payments and payoffs (9,303)
Allowance for loan losses 0
Ending Balance $ 35,439
Mortgage Loans  
Number of Properties  
Beginning balance (in properties) | Property 52
Acquisitions (in properties) | Property 0
Dispositions of real estate (in properties) | Property 0
Principal payments and payoffs (in properties) | Property (9)
Allowance for loan losses (in properties) | Property 0
Ending balance (in properties) | Property 43
Loans Receivable  
Beginning Balance $ 42,660
Acquisitions 0
Dispositions 0
Principal payments and payoffs (9,220)
Allowance for loan losses 0
Ending Balance 33,440
Other Notes  
Loans Receivable  
Beginning Balance 2,082
Acquisitions 0
Dispositions 0
Principal payments and payoffs (83)
Allowance for loan losses 0
Ending Balance $ 1,999