Note 4 - Shareholders' Equity (Details Textual) - USD ($)	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Stock Repurchased and Retired During Period, Shares	5,944	7,006
Stock Repurchased and Retired During Period, Value	$ 21,000	$ 14,000
Own-share Lending Arrangement, Shares, Outstanding	1,459,233		1,459,233

Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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