Note 12 - Intangible Assets (Details Textual) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2019	Dec. 31, 2020
Finite-Lived Intangible Assets, Net, Ending Balance	$ 9.5		$ 10.6
Finite-Lived Intangible Assets, Accumulated Amortization	14.5		$ 13.5
Amortization of Intangible Assets, Total	1.0	$ 1.0
Finite-Lived Intangible Asset, Expected Amortization, Year One	1.0
Finite-Lived Intangible Asset, Expected Amortization, after Year Five	4.5
Finite-Lived Intangible Asset, Expected Amortization, Year Two	1.0
Finite-Lived Intangible Asset, Expected Amortization, Year Three	1.0
Finite-Lived Intangible Asset, Expected Amortization, Year Four	1.0
Finite-Lived Intangible Asset, Expected Amortization, Year Five	$ 1.0

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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