Note 1 - Summary of Significant Accounting Policies - Share-based Compensation Amounts Recognized in Financial Statements (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Non-cash share-based compensation expense	$ 1,224	$ 1,514	$ 1,845
Amount of related income tax benefit	(2,081)	(3,566)	(2,310)
Net (benefit) expense to net income	$ (857)	$ (2,052)	$ (465)

Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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