Note 13 - Net Income (Loss) Per Share - Computation of Basic and Diluted Per Share Data (Details) - USD ($)
3 Months Ended 6 Months Ended 9 Months Ended
Mar. 31, 2020
Dec. 31, 2019
Mar. 31, 2019
Dec. 31, 2018
Mar. 31, 2020
Mar. 31, 2019
Sep. 30, 2019
Net Income (Loss) $ (72,000) $ 1,045,000 $ 1,773,000 $ 1,275,000 $ 973,000 $ 3,048,000 $ 6,910,000
Basic earnings (loss) per common share (in dollars per share) $ (0.01)   $ 0.27   $ 0.15 $ 0.46 $ 1.04
Diluted earnings per common share (in dollars per share) $ (0.01)   $ 0.27   $ 0.15 $ 0.46 $ 1.04
Basic (in shares) 6,567,765   6,685,415   6,567,765 6,685,415  
Incremental Common Shares Attributable to Share-based Payment Arrangements, Total (in shares)   412   87,108 360  
Diluted (in shares) 6,567,765   6,685,827   6,654,873 6,685,775