Note 12 - Accumulated Other Comprehensive Income - Components of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended	12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated other comprehensive income (loss)	$ 1,489			$ 1,178			$ 1,489	$ 1,142	$ 1,810
Other comprehensive income (loss), net of tax	(222)	$ 519	$ 50	43	$ (967)	$ 292
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated other comprehensive income (loss)				(1,846)				(1,396)	(1,897)
Other comprehensive income (loss), net of tax			1,396	(28)	100	(21)
Accumulated other comprehensive income (loss)	1,489			(668)			1,489	(254)	$ (87)
Other comprehensive income (loss), net of tax	$ (222)	$ 519	$ 1,446	$ 15	$ (867)	$ 271	$ 1,743	$ (167)