Note 14 - Financial Instruments - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Inputs, Level 1 [Member] | Reported Value Measurement [Member]
Cash and cash equivalents	$ 126,145	$ 149,173
Off-balance-sheet assets (liabilities):
Cash and cash equivalents	126,145	149,173
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	126,145	149,173
Off-balance-sheet assets (liabilities):
Cash and cash equivalents	126,145	149,173
Fair Value, Inputs, Level 2 [Member] | Reported Value Measurement [Member]
Restricted equity securities	4,357	4,135
Interest receivable	3,755	1,312
Interest payable	(40)	(45)
Off-balance-sheet assets (liabilities):
Restricted equity securities	4,357	4,135
Interest receivable	3,755	1,312
Financial liabilities:
Interest payable	(40)	(45)
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Restricted equity securities	4,357	4,135
Interest receivable	3,755	1,312
Interest payable	(40)	(45)
Off-balance-sheet assets (liabilities):
Restricted equity securities	4,357	4,135
Interest receivable	3,755	1,312
Financial liabilities:
Interest payable	(40)	(45)
Fair Value, Inputs, Level 3 [Member] | Reported Value Measurement [Member]
Loans, net	702,220	652,989
Deposits	(986,495)	(938,882)
Off-balance-sheet assets (liabilities):
Loans, net	702,220	652,989
Financial liabilities:
Deposits	(986,495)	(938,882)
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Loans, net	697,369	658,618
Deposits	(986,096)	(829,992)
Off-balance-sheet assets (liabilities):
Commitments and standby letters of credit	(1,539)	(1,180)
Loans, net	697,369	658,618
Financial liabilities:
Deposits	$ (986,096)	$ (829,992)