Note 2 - Income Tax Expense - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Details)	6 Months Ended
Jun. 30, 2020 USD ($)
Unrecognized tax benefits as of December 31, 2019	$ 848,000
Additions for tax positions of current year	0
Additions for tax positions of prior years	(4,000)
Reductions for settlements with taxing authorities	(59,000)
Reductions for lapses of the applicable statutes of limitations	0
Unrecognized tax benefits as of June 30, 2020	$ 785,000

Amount of unrecognized tax benefits.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
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-URI http://asc.fasb.org/extlink&oid=120406818&loc=SL37586934-109318

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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