Note 14 - Stock Incentive and Employee Benefit Plans - Restricted Stock Activity (Details) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restricted stock outstanding, beginning of year (in shares)	195,027	154,143	107,706
Restricted stock outstanding, beginning of year (in dollars per share)	$ 41.08	$ 37.55	$ 33.60
Restricted stock granted (in shares)	329,198	133,616	94,590
Restricted stock granted (in dollars per share)	$ 33.16	$ 41.89	$ 39.20
Restricted stock vested (in shares)	(84,044)	(82,293)	(42,310)
Restricted stock vested (in dollars per share)	$ 40.96	$ 35.75	$ 31.60
Restricted stock canceled (in shares)	(9,363)	(10,439)	(5,843)
Restricted stock canceled (in dollars per share)	$ 37.03	$ 41.26	$ 33.65
Restricted stock outstanding, end of year (in shares)	430,818	195,027	154,143
Restricted stock outstanding, end of year (in dollars per share)	$ 35.14	$ 41.08	$ 37.55