Note 1 - Description of the Business and Summary of Significant Accounting Policies - Allowance For Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts	$ 885	$ 1,462	$ 1,972
Charge-offs	(456)	(136)	(1,161)
Provision (benefit) for bad debts	294	(441)	651
Allowance for doubtful accounts	$ 723	$ 885	$ 1,462