Note 7 - Loans and the Allowance for Loan Losses - Purchased Impaired Credits (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017
Carrying amount, beginning balance		$ 696	[1]	$ 1,776
Payments received, net of discounts realized		(507)		(924)
Purchased impaired credit participation interest sales proceeds, net of discount realized		210		511
Charge-offs		(26)		(667)
Carrying amount, ending balance	[1]	10,704		$ 696
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.