XML 36 R27.htm IDEA: XBRL DOCUMENT v3.19.2
Note 3 - Certificates of Deposit (Details Textual) - USD ($)
6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Certificates Of Deposit Maximum Value Per Deposit $ 250,000    
Certificates of Deposit, at Carrying Value, Current and Noncurrent 3,404,000   $ 4,095,000
Payments to Acquire Investments, Total 2,961  
Certificates Of Deposits [Member]      
Payments to Acquire Investments, Total 979,000 2,905,000  
Proceeds from Sale, Maturity and Collection of Investments, Total $ 1,670,000 $ 2,192,890