Note 14 - Stock Plans - Summary of Stock Option Activity (Details) - Incentive and Non-Qualified Stock Options [Member]	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Stock options outstanding (in shares) | shares
Outstanding, weighted average grant date fair value (in dollars per share) | $ / shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | shares	50,000
Granted, weighted average grant date fair value (in dollars per share) | $ / shares	$ 16.97
Stock options vested (in shares) | shares
Vested, weighted average grant date fair value (in dollars per share) | $ / shares
Stock options forfeited or cancelled (in shares) | shares
Forfeited or cancelled, weighted average grant date fair value (in dollars per share) | $ / shares
Stock options outstanding (in shares) | shares	50,000
Outstanding, weighted average grant date fair value (in dollars per share) | $ / shares	$ 16.97