Note 8 - Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Jan. 14, 2005
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,100
First Mortgage Note Payable
Debt Instrument, Face Amount		$ 3,200
Long-term Debt, Maturities, Repayment Terms	The First Mortgage Note requires repayment in monthly installments of principal and interest over 20 years. On January 14, 2006 and each third anniversary thereof, the interest rate on the First Mortgage Note is adjusted to the greater of 5.75% or 3% over the Three-Year Constant Maturity Treasury Rate published by the United States Federal Reserve (“3YCMT”).
Debt Instrument, Interest Rate, Basis for Effective Rate	On January 14, 2018, the 3YCMT was 2.09% and the interest rate on the First Mortgage Note remained at 5.75% per annum. As a result, the monthly installment amount remained at $23.
Second Mortgage Note Payable
Debt Instrument, Interest Rate, Basis for Effective Rate	On October 1, 2018, the fifth anniversary of the Second Mortgage Note, the 5YCMT was 2.99%. As a result, interest was adjusted to 5.99%. The monthly installment remains at $4.
Property Carrying Value	$ 3,863
Line Of Credit 1
Debt Instrument, Interest Rate Terms	Under the line of credit agreement, interest is charged on amounts borrowed at the lender’s prime rate less 0.25%.