Note 12 - Long-term Debt - Summary of Long-term Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Long-term debt	$ 10,000
Less current portion	(10,000)	$ 0
Long-term debt, noncurrent	$ 0	55,000
Line of Credit [Member]
Long-term debt, weighted average interest rate	3.10%
Long-term debt, maturities	2020
Long-term debt	$ 10,000	$ 55,000