Note 9 - Stockholders' Equity - Summary of Repurchases (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Shares of common stock repurchased (in shares)	20,524	21,410
Average per share repurchase price (in dollars per share)	$ 33.28	$ 34.62
Aggregage purchase price (in thousands)	$ 683	$ 741

Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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