Note 12 - Income Taxes (Details Textual) $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($)
Income Tax Examination, Penalties and Interest Expense, Total	$ 2.1
Open Tax Year	2015 2016 2017 2018 2019

The sum of the amounts of estimated penalties and interest recognized in the period arising from income tax examinations.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319

Name:	us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration