Note 5 - Loans - Troubled Debt Restructuring Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Charge-offs	$ (1,780)	$ (752)	$ (5,600)
Accruing Troubled Debt Restructuring [Member]
Beginning balance	81,680	104,356	117,597
New restructurings	26,965	17,752	23,740
Restructured loans restored to accrual status	10,303	723	962
Charge-offs	(88)	(104)
Payments	(24,192)	(30,858)	(13,256)
Restructured loans placed on non-accrual	(13,984)	(10,189)	(24,687)
Expiration of loan concession	(15,291)
Ending balance	65,393	81,680	104,356
Restructured loans placed on non-accrual	13,984	10,189	24,687
Restructured loans restored to accrual status	(10,303)	(723)	(962)
Non-accruing Troubled Debt Restructuring [Member]
Beginning balance	39,923	41,618	38,769
New restructurings	6,940	2,006	1,331
Restructured loans restored to accrual status	10,303	723	962
Charge-offs	(5,271)	(3,246)	(8,938)
Payments	(15,551)	(9,921)	(11,710)
Restructured loans placed on non-accrual	(13,984)	(10,189)	(24,688)
Ending balance	29,722	39,923	41,618
Restructured loans placed on non-accrual	13,984	10,189	24,688
Foreclosures			(1,560)
Restructured loans restored to accrual status	$ (10,303)	$ (723)	$ (962)