Quarterly report pursuant to Section 13 or 15(d)

Debt (Narrative) (Details)

v3.8.0.1
Debt (Narrative) (Details) - USD ($)
3 Months Ended 9 Months Ended
Mar. 31, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Debt Instrument [Line Items]        
Mortgage principal payments     $ 103,603  
Mortgage [Member]        
Debt Instrument [Line Items]        
Interest rate   6.83%    
Maturity date   Mar. 01, 2016    
Mortgage principal payments $ 104,000      
Line of Credit [Member]        
Debt Instrument [Line Items]        
Line of credit, maximum borrowing capacity   $ 15,000,000    
Line of credit, amount outstanding   0   $ 0
Line of credit, remaining borrowing capacity   $ 11,200,000    
Line of credit facility, interest rate at period end   3.20%    
Line of credit, expiration date   Aug. 12, 2021    
Minimum liquidity   $ 10,000,000    
Line of Credit [Member] | LIBOR [Member]        
Debt Instrument [Line Items]        
Line of credit, basis spread on variable rate   2.00%