XML 26 R79.htm IDEA: XBRL DOCUMENT v3.20.1
Unsecured Lines of Credit - Additional Information (Details) - USD ($)
3 Months Ended
Mar. 31, 2020
Apr. 30, 2020
Dec. 31, 2019
Line Of Credit Facility [Line Items]      
Lines of credit $ 12,540,000   $ 13,200,000
Bankers Trust Operating [Member]      
Line Of Credit Facility [Line Items]      
Lines of credit $ 0    
Bankers Trust Operating [Member] | Subsequent Event [Member]      
Line Of Credit Facility [Line Items]      
Lines of credit   $ 0  
Bankers Trust Non-operating [Member]      
Line Of Credit Facility [Line Items]      
Debt instrument, maturity date Jun. 30, 2020    
Debt instrument, maturity date, description The outstanding balance of the non-operating LOC as of March 31, 2020 is due in June 2020, though the Partnership can extend final repayment of the amount due to December 2020 by making partial repayments.