Note 9 - Borrowings - Outstanding Advances (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Advances from FHLB	$ 15,100,000	$ 1,100,000
Federal Home Loan Bank of Chicago [Member]
Open lines of credit at 1.46%	4,000,000
Advances from FHLB	15,105,287	1,121,153
Federal Home Loan Bank of Chicago [Member] | Matures 02/15/2018 at 1.27% [Member]
Advances from FHLB	1,000,000
Federal Home Loan Bank of Chicago [Member] | Matures 03/30/2018 at 1.72% [Member]
Advances from FHLB	499,357	496,784
Federal Home Loan Bank of Chicago [Member] | Matures 05/15/2018 at 1.34% [Member]
Advances from FHLB	2,000,000
Federal Home Loan Bank of Chicago [Member] | Matures 08/30/2019 at 1.56% [Member]
Advances from FHLB	3,000,000
Federal Home Loan Bank of Chicago [Member] | Matures 09/25/2018 at 1.46% [Member]
Advances from FHLB	2,000,000
Federal Home Loan Bank of Chicago [Member] | Matures 04/01/2019 at 2.00% [Member]
Advances from FHLB	497,089	494,906
Federal Home Loan Bank of Chicago [Member] | Matures 12/16/2019 at 2.08% [Member]
Advances from FHLB	2,000,000
Federal Home Loan Bank of Chicago [Member] | Matures 10/03/2022 at 1.48% [Member]
Advances from FHLB	$ 108,841	$ 129,463