Note 8 - Fair Value Measurements - Fair Value of Financial Instruments Measured on a Non-recurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Reported Value Measurement [Member]
Other real estate owned		$ 1,030	$ 697
Impaired loans, net	[1]	1,621	3,916
Total assets		2,651	4,613
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Other real estate owned		0	0
Impaired loans, net	[1]	0	0
Total assets		0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Other real estate owned		0	0
Impaired loans, net	[1]	0	0
Total assets		0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Other real estate owned		1,030	697
Impaired loans, net	[1]	1,621	3,916
Total assets		$ 2,651	$ 4,613

[1] mount is net of a valuation allowance of $768,000 at September 30, 2020 and $1,136,000 at December 31, 2019 as required by ASC 310, “Receivables.”