Note 3 - Loans Held for Investment, Net - Impaired Loans (Details) - USD ($)	9 Months Ended	12 Months Ended
Sep. 30, 2017	Dec. 31, 2016
Impaired Loans, With an Allowance Recorded, Recorded Investment	$ 0	$ 0
Impaired Loans, With an Allowance Recorded, Principal Net of Charge-offs	0	0
Impaired Loans, Related Allowance	0	0
Impaired Loans, With an Allowance Recorded, Average Recorded Investment	0	0
Commercial Real Estate Portfolio Segment [Member]
Impaired Loans, With no Related Allowance Recorded, Recorded Investment	3,576,297	3,718,686
Impaired Loans, With no Related Allowance Recorded, Principal Net of Charge-offs,	3,576,297	3,718,686
Impaired Loans, With no Related Allowance Recorded, Average Recorded Investment	3,627,001	1,385,277
Impaired Loans, Related Allowance	0	0
Impaired Loans, Recorded Investment	3,576,297	3,718,686
Impaired Loans, Principal Net of Charge-offs	3,576,297	3,718,686
Impaired Loans, Average Recorded Investment	3,627,001	1,385,277
One-to-four Family Residential Real Estate Portfolio Segment [Member]
Impaired Loans, With no Related Allowance Recorded, Recorded Investment	657,421	648,880
Impaired Loans, With no Related Allowance Recorded, Principal Net of Charge-offs,	657,421	648,880
Impaired Loans, With no Related Allowance Recorded, Average Recorded Investment	665,003	656,495
Impaired Loans, Related Allowance	0	0
Impaired Loans, Recorded Investment	657,421	648,880
Impaired Loans, Principal Net of Charge-offs	657,421	648,880
Impaired Loans, Average Recorded Investment	665,003	656,495
Commercial and Industrial Portfolio Segment [Member]
Impaired Loans, With no Related Allowance Recorded, Recorded Investment	1,568,908	1,600,655
Impaired Loans, With no Related Allowance Recorded, Principal Net of Charge-offs,	1,568,908	1,600,655
Impaired Loans, With no Related Allowance Recorded, Average Recorded Investment	1,591,938	1,075,536
Impaired Loans, Related Allowance	0	0
Impaired Loans, Recorded Investment	1,568,908	1,600,655
Impaired Loans, Principal Net of Charge-offs	1,568,908	1,600,655
Impaired Loans, Average Recorded Investment	1,591,938	1,075,536
Consumer and Other Portfolio Segment [Member]
Impaired Loans, With no Related Allowance Recorded, Recorded Investment	0	0
Impaired Loans, With no Related Allowance Recorded, Principal Net of Charge-offs,	0	0
Impaired Loans, With no Related Allowance Recorded, Average Recorded Investment	0	0
Impaired Loans, Related Allowance	0	0
Impaired Loans, Recorded Investment	0	0
Impaired Loans, Principal Net of Charge-offs	0	0
Impaired Loans, Average Recorded Investment	$ 0	$ 0

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

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