Note 7 - Loans - Troubled Debt Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Charge-offs
Accruing Troubled Debt Restructuring [Member]
Beginning balance	65,393	$ 81,680
New restructurings	27,683
Restructured loans restored to accrual status		10,303
Payments	(4,595)	(1,811)
Restructured loans placed on non-accrual status	(5,822)
Expiration of loan concession upon renewal	(2,240)
Ending balance	80,419	90,172
Non-accruing Troubled Debt Restructuring [Member]
Beginning balance	29,722	39,923
New restructurings
Restructured loans restored to accrual status	5,822
Payments	(990)	(6,411)
Restructured loans placed on non-accrual status		(10,303)
Ending balance	32,779	23,209
Charge-offs	(1,049)
Foreclosures	$ (726)