Note 8 - Stock-based Compensation - Stock Option Activity (Details)	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Options outstanding, January 1, 2016 (none exercisable) (in shares) | shares
Options outstanding, January 1, 2016 (none exercisable) (in dollars per share) | $ / shares
Granted (in shares) | shares	19,800
Granted (in dollars per share) | $ / shares	$ 4.37
Options outstanding, June 30, 2016 (none exercisable) (in shares) | shares	19,800
Options outstanding, June 30, 2016 (none exercisable) (in dollars per share) | $ / shares	$ 4.37