Note 1 - Summary of Significant Accounting Policies - Summary of Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Beginning balance	$ 1,857	$ 1,767	$ 1,736
Provision (reversal) for losses on accounts receivable	(241)	1,100	774
Write-offs and other deductions	(271)	(1,010)	(743)
Ending balance	$ 1,345	$ 1,857	$ 1,767