Note 23 - Acquisition (Details Textual) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2019	Dec. 31, 2018
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares		1,834,142
Goodwill, Amortization period			15 years
Core Deposits [Member]
Finite-Lived Intangible Assets, Gross, Total			$ 1,804
Finite-Lived Intangible Asset, Useful Life			8 years
Subsequent Event [Member] | Merchants Holding Company [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total	$ 211,660	$ 211,660
Subsequent Event [Member] | Bank of Commerce [Member] | Merchants Holding Company [Member]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	10.00%	10.00%
Merchants Holding Company [Member] | Subsequent Event [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total	$ 215,015	$ 215,015
Payments to Acquire Businesses, Gross	$ 15,300	$ 15,300
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	1,834,142	1,834,142
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans	$ 85,300	$ 85,300
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deposits	190,200	190,200
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Investment Securities	107,400	107,400
Goodwill, Ending Balance	11,039	$ 11,039
Goodwill, Amortization period		15 years
Business Acquisition, Transaction Costs	1,300	$ 1,300
Merchants Holding Company [Member] | Subsequent Event [Member] | Core Deposits [Member]
Finite-Lived Intangible Assets, Gross, Total	$ 4,400	$ 4,400
Finite-Lived Intangible Asset, Useful Life		8 years
Impairment of Intangible Assets, Finite-lived		$ 0