Note 3 - Acquisition of Fairmount Bancorp, Inc. - Allocation of Preliminary Purchase Price (Details) - USD ($)	Mar. 31, 2016	Sep. 11, 2015	Mar. 31, 2015	Mar. 31, 2014
Fairmount Bancorp, Inc. [Member] | Reported Value Measurement [Member]
Cash and cash equivalents		$ 1,468,499
Certificates of deposit		4,467,825
Investment securities available for sale		9,729,405
Loans		55,454,414
Allowance For Loan Loss		(591,070)
Premises and equipment		2,975,587
Core Deposit Intangible		22,802
Deferred income taxes		423,258
Other assets		1,031,755
Total identifiable assets		74,982,475
Identifiable liabilities:
Non-interest bearing deposits		909,669
Interest bearing deposits		52,123,868
Borrowings		10,500,000
Other liabilities		120,351
Total identifiable liabilities		63,653,888
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		$ 11,328,587
Definite lived intangible assets acquired
Goodwill
Net intangible assets acquired
Total cash consideration		$ 11,328,587
Fairmount Bancorp, Inc. [Member] | Fair Value Adjustments [Member]
Cash and cash equivalents
Certificates of deposit		$ 27,772
Investment securities available for sale
Loans		$ (1,425,279)
Allowance For Loan Loss		591,070
Premises and equipment		(726,997)
Core Deposit Intangible		(22,802)
Deferred income taxes		$ 596,675
Other assets
Total identifiable assets		$ (959,561)
Identifiable liabilities:
Non-interest bearing deposits
Interest bearing deposits		$ 433,429
Borrowings		$ 389,147
Other liabilities
Total identifiable liabilities		$ 822,576
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		(1,782,137)
Definite lived intangible assets acquired		542,540
Goodwill		4,103,379
Net intangible assets acquired		4,645,919
Total cash consideration		2,863,782
Fairmount Bancorp, Inc. [Member]
Cash and cash equivalents		1,468,499
Certificates of deposit		4,495,597
Investment securities available for sale		9,729,405
Loans		$ 54,029,135
Allowance For Loan Loss
Premises and equipment		$ 2,248,590
Core Deposit Intangible
Deferred income taxes		$ 1,019,933
Other assets		1,031,755
Total identifiable assets		74,022,914
Identifiable liabilities:
Non-interest bearing deposits		909,669
Interest bearing deposits		52,557,297
Borrowings		10,889,147
Other liabilities		120,351
Total identifiable liabilities		64,476,464
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		9,546,450
Definite lived intangible assets acquired		542,540
Goodwill		4,103,379
Net intangible assets acquired		4,645,919
Total cash consideration		14,192,369
Investment securities available for sale	$ 70,484,400		$ 92,939,751
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		$ 9,500,000
Goodwill	$ 6,767,811		$ 2,664,432	$ 2,664,432