Note 7 - Loans and the Allowance for Loan Losses - Purchased Impaired Credits (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018
Carrying amount, beginning balance		$ 10,704	[1]	$ 696
Payments received, net of discounts realized		(5,695)		(507)
Purchased impaired credit participation interest sales proceeds, net of discount realized				210
Charge-offs				(26)
Carrying amount, ending balance	[1]	$ 5,009		10,704
Minden Bancorp [Member]
Carrying amount of purchased impaired credits acquired in acquisition				5,798
Richland State Bancorp [Member]
Carrying amount of purchased impaired credits acquired in acquisition				$ 4,533

[1] Purchased credit impaired loans are evaluated for impairment on an individual basis.