Quarterly report pursuant to Section 13 or 15(d)

Borrowings - Additional Information (Details)

v3.10.0.1
Borrowings - Additional Information (Details)
3 Months Ended 9 Months Ended
Sep. 30, 2018
USD ($)
debt_instrument
Sep. 30, 2017
Sep. 30, 2018
USD ($)
debt_instrument
Sep. 30, 2017
Sep. 13, 2018
USD ($)
Aug. 17, 2018
USD ($)
Jul. 30, 2018
USD ($)
Jul. 12, 2018
USD ($)
Mar. 13, 2018
USD ($)
Dec. 31, 2017
USD ($)
May 31, 2017
debt_instrument
Dec. 05, 2014
USD ($)
Debt Instrument [Line Items]                        
Weighted average interest rate (as percent) 3.76% 3.44% 3.63% 3.33%                
Borrowings under lines of credit $ 100,000   $ 100,000             $ 10,000,000    
Farm Credit FL Note Payable Issued July 12, 2018                        
Debt Instrument [Line Items]                        
Face amount of debt               $ 16,850,000        
Farm Credit Notes Payable                        
Debt Instrument [Line Items]                        
Reduction in basis points (as percent)     0.71%                  
Number of debt instruments | debt_instrument 18   18                  
Metlife Term Loans | Notes and bonds payables                        
Debt Instrument [Line Items]                        
Number of debt instruments | debt_instrument                     2  
MetLife Facility                        
Debt Instrument [Line Items]                        
Face amount of debt $ 200,000,000   $ 200,000,000                  
Revolving equity lines of credit borrowing capacity 75,000,000   75,000,000                  
New MetLife Facility | Notes and bonds payables                        
Debt Instrument [Line Items]                        
Face amount of debt $ 200,000,000   $ 200,000,000                  
Farmer Mac Bonds Payable                        
Debt Instrument [Line Items]                        
Face amount of debt                 $ 125,000,000     $ 125,000,000
Number of debt instruments | debt_instrument 16   16                  
Farmer Mac Bonds Payable, 2018 Issuances                        
Debt Instrument [Line Items]                        
Face amount of debt         $ 4,110,000 $ 7,050,000 $ 10,356,000   $ 1,260,000      
Number of debt instruments | debt_instrument 4   4                  
Mortgage notes and bonds payable | Notes and bonds payables                        
Debt Instrument [Line Items]                        
Aggregate fair value of mortgage notes payable outstanding $ 302,700,000   $ 302,700,000                  
Mortgage notes payable, carrying value 318,400,000   318,400,000                  
Short-term variable-rate mortgage notes and bonds payable | Notes and bonds payables                        
Debt Instrument [Line Items]                        
Borrowings under lines of credit $ 100,000   $ 100,000