Note 4 - Investments (Details Textual) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2022
Other than Temporary Impairment Loss, Investments, Portion in Other Comprehensive Loss, Net of Tax, Attributable to Parent, Held-to-Maturity Securities	$ 0	$ 0

Amount after tax of amount of other than temporary impairment (OTTI) on investment in held-to-maturity debt security, recognized in other comprehensive loss, attributable to parent entity.

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-SubTopic 10
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration