Note 8 - Commitments - Summary of Information Regarding Derivatives (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Customer Interest Rate Swap Maturing in 2020 [Member]
Notional Amount	$ 2,236	$ 2,312
Fair Value	6	4
Customer Interest Rate Swap Maturing in 2025 [Member]
Notional Amount	4,267	4,557
Fair Value	321	134
Customer Interest Rate Swap Maturing in 2026 [Member]
Notional Amount	1,726	1,822
Fair Value	118	19
Customer Interest Rate Swap Maturing in 2027 [Member]
Notional Amount	13,032	13,363
Fair Value	1,567	636
Customer Interest Rate Swap Maturing in 2028 [Member]
Notional Amount	6,040	6,068
Fair Value	1,055	548
Customer Interest Rate Swap Maturing in 2029 [Member]
Notional Amount	3,659	3,721
Fair Value	338	(19)
Customer Interest Rate Swap Maturing in 2030 [Member]
Notional Amount	5,983	3,649
Fair Value	443	44
Customer Interest Rate Swap Maturing in 2032 [Member]
Notional Amount	2,551	0
Fair Value	204	0
Customer Interest Rate Swap Maturing in 2033 [Member]
Notional Amount	1,102	1,121
Fair Value	187	56
Customer Interest Rate Swap [Member]
Notional Amount	40,596	36,613
Fair Value	4,239	1,422
Third Party Interest Rate Swap Maturing in 2020 [Member]
Notional Amount	2,236	2,312
Fair Value	(6)	(4)
Third Party Interest Rate Swap Maturing in 2025 [Member]
Notional Amount	4,267	4,557
Fair Value	(321)	(134)
Third Party Interest Rate Swap Maturing in 2026 [Member]
Notional Amount	1,726	1,822
Fair Value	(118)	(19)
Third Party Interest Rate Swap Maturing in 2027 [Member]
Notional Amount	13,032	13,363
Fair Value	(1,567)	(636)
Third Party Interest Rate Swap Maturing in 2028 [Member]
Notional Amount	6,040	6,068
Fair Value	(1,055)	(548)
Third Party Interest Rate Swap Maturing in 2029 [Member]
Notional Amount	3,659	3,721
Fair Value	(338)	19
Third Party Interest Rate Swap Maturing in 2030 [Member]
Notional Amount	5,983	3,649
Fair Value	(443)	(44)
Third Party Interest Rate Swap Maturing in 2032 [Member]
Notional Amount	2,551	0
Fair Value	(204)	0
Third Party Interest Rate Swap Maturing in 2033 [Member]
Notional Amount	1,102	1,121
Fair Value	(187)	(56)
Third Party Interest Rate Swap [Member]
Notional Amount	40,596	36,613
Fair Value	$ (4,239)	$ (1,422)