Note 11 - Stock-Based Compensation - Non-Vested Restricted Stock (Details) - Restricted Stock [Member]	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Non-vested at December 31, 2017 (in shares) | shares	155
Non-vested at December 31, 2017 (in dollars per share) | $ / shares	$ 876
Granted (in shares) | shares	290,300
Granted (in dollars per share) | $ / shares	$ 876
Vested (in shares) | shares	(155)
Vested (in dollars per share) | $ / shares	$ 876
Non-vested at December 31, 2018 (in shares) | shares	290,300
Non-vested at December 31, 2018 (in dollars per share) | $ / shares	$ 3.45