Note 10 - Income Taxes (Details Textual)	Dec. 31, 2020 USD ($)
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	$ 31,116,000

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are subject to expiration dates.

No definition available.

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant