Note 9 - Borrowings - Outstanding Advances (Details) (Parentheticals) - Federal Home Loan Bank of Chicago [Member]	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Matures 03/15/2019 at 2.42% [Member]
Maturity date on fixed rate advance		Mar. 15, 2019
Interest rate, fixed		2.42%
Matures 04/01/2019 at 2.00% [Member]
Maturity date on fixed rate advance		Apr. 01, 2019
Interest rate, fixed		2.00%
Matures 08/30/2019 at 1.56% [Member]
Maturity date on fixed rate advance		Aug. 30, 2019
Interest rate, fixed		1.56%
Matures 12/16/2019 at 2.08% [Member]
Maturity date on fixed rate advance		Dec. 16, 2019
Interest rate, fixed		2.08%
Matures 03/22/2021 at 3.03% [Member]
Maturity date on fixed rate advance	Mar. 22, 2021	Mar. 22, 2021
Interest rate, fixed	3.03%	3.03%
Matures 09/21/2021 at 3.07% [Member]
Maturity date on fixed rate advance	Sep. 21, 2021	Sep. 21, 2021
Interest rate, fixed	3.07%	3.07%
Matures 03/21/2022 at 3.09% [Member]
Maturity date on fixed rate advance	Mar. 21, 2022	Mar. 21, 2022
Interest rate, fixed	3.09%	3.09%
Matures 09/21/2022 at 3.11% [Member]
Maturity date on fixed rate advance	Sep. 21, 2022	Sep. 21, 2022
Interest rate, fixed	3.11%	3.11%
Matures 10/03/2022 at 1.48% [Member]
Maturity date on fixed rate advance	Oct. 03, 2022	Oct. 03, 2022
Interest rate, fixed	1.48%	1.48%
Matures 03/21/2023 at 3.15% [Member]
Maturity date on fixed rate advance	Mar. 21, 2023	Mar. 21, 2023
Interest rate, fixed	3.15%	3.15%
Matures 09/21/2023 at 3.18 % [Member]
Maturity date on fixed rate advance	Sep. 21, 2023	Sep. 21, 2023
Interest rate, fixed	3.18%	3.18%
Matures 08/28/2024 at 1.59% [Member]
Maturity date on fixed rate advance	Aug. 28, 2024	Aug. 28, 2024
Interest rate, fixed	1.59%	1.59%
Matures 08/28/2029 at 1.93% [Member]
Maturity date on fixed rate advance	Aug. 28, 2029	Aug. 28, 2029
Interest rate, fixed	1.93%	1.93%
Matures 10/23/2029 at 1.96% [Member]
Maturity date on fixed rate advance	Oct. 23, 2029	Oct. 23, 2029
Interest rate, fixed	1.96%	1.96%