Note 5 - Share-based Compensation and Employee Benefit Plan - Restricted Shares (Details) - Restricted Stock [Member] - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Unvested at beginning of year, weighted average grant date fair value (in dollars per share)	$ 12.55	$ 14.06	$ 12.84	$ 12.83
Unvested at end of year, weighted average grant date fair value (in dollars per share)	$ 12.39	$ 14.16	$ 12.39	$ 14.16
Unvested at beginning of year (in shares)	33,033	113,938	35,264	55,854
Granted (in shares)	5,084		5,084	58,084
Granted, weighted average grant date fair value (in dollars per share)	$ 15.05		$ 15.05	$ 15.25
Vested (in shares)		(2,526)	(2,231)	(2,526)
Vested, weighted average grant date fair value (in dollars per share)		$ 14.72	$ 13.05	$ 14.72
Forfeited (in shares)	(6,000)	(4,213)	(6,000)	(4,213)
Forfeited, weighted average grant date fair value (in dollars per share)	$ 15.50	$ 11.31	$ 15.50	$ 11.31
Unvested at end of year (in shares)	32,117	107,199	32,117	107,199