Note 14 - Net Income Per Share - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Parent Company [Member]
Net income	$ 10,109	$ 9,002	$ 19,944	$ 18,257
Net income	$ 10,109	$ 9,002	$ 19,944	$ 18,257
Basic (in shares)	22,336	22,065	22,295	22,018
Dilutive securities (in shares)	368	339	363	335
Average shares outstanding including dilutive securities including dilutive securities (in shares)	22,704	22,404	22,658	22,353
Basic (in dollars per share)	$ 0.45	$ 0.41	$ 0.89	$ 0.83
Diluted (in dollars per share)	$ 0.45	$ 0.40	$ 0.88	$ 0.82