Note 8 - Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Unrecognized tax benefits at the beginning of year	$ 711	$ 525	$ 390
Additions for tax positions of current year	74	73	83
Additions for tax positions of prior years	63	113	57
Reductions for settlements with taxing authorities.
Reductions for lapses of the applicable statutes of limitations			(5)
Unrecognized tax benefits at the end of the year	$ 848	$ 711	$ 525

Amount of unrecognized tax benefits.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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