Note 9 - Fair Values - Fair Value of Assets Measured on a Non-recurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Other real estate owned	[1]	$ 0		$ 8
Other real estate owned, fair value adjustment		8	$ 6
Total assets measured at fair value	[1]	0		$ 8
Other Real Estate Owned [Member]
Other real estate owned, fair value adjustment		$ 8	$ 6

[1] Fair value is presented on a nonrecurring basis - Level 3.