Note 7 - Loans - Troubled Debt Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accruing Troubled Debt Restructuring [Member]
Beginning balance	$ 74,708	$ 100,011	$ 81,680	$ 104,355
New restructurings	18,347	427	20,412	16,853
Restructured loans restored to accrual status		723	10,303	723
Charge-offs				(148)
Payments	(6,500)	(11,280)	(9,816)	(21,714)
Restructured loans placed on non-accrual status			(1,138)	(10,188)
Expiration of loan concession upon renewal			(14,886)
Ending balance	86,555	89,881	86,555	89,881
Non-accruing Troubled Debt Restructuring [Member]
Beginning balance	25,442	42,595	39,923	41,618
New restructurings	649	1,796	3,794	2,006
Restructured loans restored to accrual status			1,138	10,188
Charge-offs	(3,407)	(3)	(4,352)	(3,246)
Payments	(1,814)	(1,859)	(9,330)	(8,037)
Restructured loans placed on non-accrual status		(723)	(10,303)	(723)
Ending balance	20,870	41,806	20,870	41,806
Charge-offs				$ (148)