Note 2 - Accounts Receivable (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable, Current	$ 3,100	$ 2,900
Provision for Doubtful Accounts	$ 506	$ 467	$ 83