Note 16 - Amounts Reclassified Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Total other-than-temporary impairment loss on investment securities												$ (80,000)
Income before income taxes		$ 3,368,000	$ 3,821,000	$ 3,822,000	$ 4,196,000	$ 1,988,000	$ 3,978,000	$ 3,434,000	$ 3,492,000	$ 15,207,000	$ 12,892,000	14,189,000
Tax effect		(623,000)	(731,000)	(679,000)	(817,000)	339,000	(767,000)	(572,000)	(557,000)	(2,850,000)	(1,557,000)	(5,900,000)
Net income		$ 2,745,000	$ 3,090,000	$ 3,143,000	$ 3,379,000	$ 2,327,000	$ 3,211,000	$ 2,862,000	$ 2,935,000	12,357,000	11,335,000	8,289,000
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Realized net holding (losses) gains on available-for-sale securities										(26,000)	3,000	1,580,000
Total other-than-temporary impairment loss on investment securities												(80,000)
Income before income taxes										(26,000)	3,000	1,500,000
Tax effect	[1]									5,000	(1,000)	(510,000)
Net income										$ (21,000)	$ 2,000	$ 990,000

[1] At rate of 21% for both 2019 and 2018 and 34% for 2017