Note 1 - Significant Accounting Policies - Depreciation of Property, Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2020
Minimum [Member] | Building and Building Improvements [Member]
Estimated useful life (Year)	10 years
Minimum [Member] | Machinery and Equipment [Member]
Estimated useful life (Year)	3 years
Maximum [Member] | Building and Building Improvements [Member]
Estimated useful life (Year)	45 years
Maximum [Member] | Machinery and Equipment [Member]
Estimated useful life (Year)	25 years