Note 20 - Assets and Liabilities Measured and Reported at Fair Value (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Impaired Financing Receivable, Related Allowance	$ 42	$ 48
Impaired Financing Receivable, with Related Allowance, Recorded Investment	42	48
Other Real Estate, Foreclosed Assets, and Repossessed Assets, Total	1,000	2,600
Impaired Loans [Member] | Appraisal Discount Method [Member]
Assets, Fair Value Disclosure	925	2,600
Impaired Financing Receivable, Related Allowance	42	48
Impaired Financing Receivable, with Related Allowance, Recorded Investment	967	2,600
Mortgage Servicing Rights [Member]
Impaired Financing Receivable, Related Allowance	0	0
Fair Value, Measurements, Recurring [Member]
Assets, Fair Value Disclosure	438,030	575,103	[1]
Interest Rate Derivative Assets, at Fair Value	1,035	579
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Assets, Fair Value Disclosure	438,030	425,119	[1]
Interest Rate Derivative Assets, at Fair Value	1,035	579
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Assets, Fair Value Disclosure	0	0
Interest Rate Derivative Assets, at Fair Value
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 0	0
Previously Reported [Member]
Assets, Fair Value Disclosure		575,079
Interest Rate Derivative Assets, at Fair Value		259
Previously Reported [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure		$ 425,095

[1] December 31, 2017 fair value balances reflect a correction of incorrectly reported year-end balances in Note 20 of the 2017 Form 10-K, which were presented as $575,079, $425,095, and $259, for total assets, total level 2 assets, and interest rate swap liabilities, respectively.