Note 9 - Subsequent Events (Details Textual) - Subsequent Event [Member] - USD ($) $ / shares in Units, $ in Millions	Jul. 26, 2019	Jul. 22, 2019
Dividends Payable, Amount Per Share		$ 0.27
Dividends Payable		$ 5.4
Dividends Payable, Date Declared		Jul. 22, 2019
Dividends Payable, Date of Record		Aug. 02, 2019
Dividends Payable, Date to be Paid		Aug. 09, 2019
Restricted Stock [Member] \| 2016 Employee Equity Compensation Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	37,125
Chief Executive Officer [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	40,000
Director [Member] \| Restricted Stock [Member] \| 2015 Outside Director Equity Compensation Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	37,500

Date the declared dividend will be paid, in CCYY-MM-DD format.

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