Note 8 - Loans (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Impaired Financing Receivable, Recorded Investment, Total	$ 119,646	$ 106,886
Percentage Of Charge Off To Contractual Balances For Impaired Loans	9.90%	9.30%
Financing Receivable, Troubled Debt Restructuring, Commitment to Lend	$ 0
Minimum [Member]
Period Loan Is In Payment Default	60 days
Maximum [Member]
Period Loan Is In Payment Default	90 days
Nonaccrual Loans [Member]
Impaired Financing Receivable, Recorded Investment, Total	$ 54,700	$ 41,800
Accruing Troubled Debt Restructuring [Member]
Impaired Financing Receivable, Recorded Investment, Total	64,900	65,100
Financing Receivable, Troubled Debt Restructuring	64,900	65,100
Troubled Debt Restructuring, Specific Reserves	1,300	1,500
Non-accruing Troubled Debt Restructuring [Member]
Financing Receivable, Troubled Debt Restructuring	22,500	24,200
Troubled Debt Restructuring, Specific Reserves	$ 54	$ 826