Note 12 - "At the Market" Stock Offering Program (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	May 31, 2017
Proceeds from Issuance of Common Stock	$ (35)	$ 0
At-The-Market Offering [Member]
Stock Issued During Period, Shares, New Issues	118,700
Proceeds from Issuance of Common Stock	$ 1,800
Common Stock, Value, Subscriptions			$ 40,000
Sale of Stock, Price Per Share	$ 16.90
Sales Commissions and Fees	$ 200
At The Market Equity Offering Remaining Authorized Amount Value	$ 38,000