Note 8 - Loans - Troubled Debt Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Charge-offs	$ (811)	$ 0	$ (811)	$ 0
Accruing Troubled Debt Restructuring [Member]
Beginning balance	62,948	82,785	65,071	68,566
New restructurings	13,244	5,127	15,192	22,447
Restructured loans restored to accrual status	0	0	0	2,318
Payments	(9,998)	(2,855)	(14,069)	(6,746)
Restructured loans placed on non-accrual status	(1,296)	(570)	(1,296)	(2,098)
Ending balance	64,898	84,487	64,898	84,487
Non-accruing Troubled Debt Restructuring [Member]
Beginning balance	23,301	31,195	24,189	33,415
New restructurings	3,160	0	3,160	231
Restructured loans restored to accrual status	0	0	0	(2,318)
Payments	(4,489)	(1,257)	(4,970)	(2,918)
Restructured loans placed on non-accrual status	1,296	570	1,296	2,098
Ending balance	22,457	30,347	22,457	30,347
Charge-offs	$ (811)	$ (161)	$ (1,218)	$ (161)