Note 12 - Stock Based Compensation - Additional Shares Authorized (Details) - shares	12 Months Ended							84 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2017
The 2010 Stock Option and Incentive Plan [Member]
Total additional shares (in shares)	106,076	12,623	18,368	5,463	4,128	2,871	2,502	152,031