XML 42 R31.htm IDEA: XBRL DOCUMENT v3.19.2
Note 6 - Debt (Details Textual) - USD ($)
Mar. 25, 2019
Sep. 11, 2018
Jun. 30, 2019
Jan. 31, 2019
Dec. 31, 2018
Line of Credit, Current     $ 500,000  
Revolving Credit Facility [Member]          
Line of Credit Facility, Maximum Borrowing Capacity $ 750,000 $ 750,000 750,000 $ 750,000  
Line of Credit, Current     $ 500,000 $ 500,000 $ 0
Debt Instrument, Interest Rate, Stated Percentage     5.48%    
Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]          
Debt Instrument, Basis Spread on Variable Rate 3.00% 2.25%