Note 2 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Gain on equity securities	[1]	$ (160,000)	$ 58,000
Earnings on bank-owned life insurance	[1]	107,000	105,000
Gain on sale of loans	[1]	114,000	59,000
Revenue from investment services		131,000	138,000
Other income		329,000	264,000
Total noninterest income		1,074,000	1,132,000
Net gain on other real estate owned			43,000
Overdraft Fees [Member]
Noninterest income revenue		190,000	248,000
ATM Banking Fees [Member]
Noninterest income revenue		210,000	194,000
Service Charge and Other Fees [Member]
Noninterest income revenue		$ 153,000	$ 66,000

[1] Not within scope of ASC 606