Note 17 - Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Impaired loans	$ 2,880,000	$ 1,107,000
Foreclosed assets	701,000	452,000
Total	3,581,000	1,559,000
Fair Value, Inputs, Level 1 [Member]
Impaired loans	0	0
Foreclosed assets	0	0
Total	0	0
Fair Value, Inputs, Level 2 [Member]
Impaired loans	0	0
Foreclosed assets	0	0
Total	0	0
Fair Value, Inputs, Level 3 [Member]
Impaired loans	2,880,000	1,107,000
Foreclosed assets	701,000	452,000
Total	$ 3,581,000	$ 1,559,000