Note 10 - Taxes - Tax Examinations (Details)	3 Months Ended
	Mar. 31, 2021
Domestic Tax Authority [Member]
Open tax year	2017
Foreign Tax Authority [Member] | State Administration of Taxation, China [Member]
Open tax year	2017
Foreign Tax Authority [Member] | Departamento de Hacienda de Puerto Rico [Member]
Open tax year	2015
Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Open tax year	2015
State and Local Jurisdiction [Member]
Open tax year	2016