Note 10 - Goodwill and Other Intangible Asset - Activity in Goodwill and Acquired Intangible Assets Related to Branch Purchase (Details) - USD ($)		12 Months Ended
	Sep. 11, 2015	Mar. 31, 2017		Mar. 31, 2016
Goodwill, Beginning Balance		$ 6,767,811		$ 2,664,432
Goodwill, Additions		1,877,243	[1]	4,103,379	[2]
Goodwill, Post acquisition adjustments		(81,524)
Core deposit intangible, Ending Balance		739,298
Core deposit intangible, Amortization		(121,022)		(62,573)
Goodwill, Ending Balance		8,563,530		6,767,811
Core Deposits [Member]
Core deposit intangible, Beginning Balance		618,300		138,333
Core deposit intangible, Additions	$ 543,000	242,020	[1]	542,540	[2]
Core deposit intangible, Post acquisition adjustments
Core deposit intangible, Ending Balance		739,298		618,300
Core deposit intangible, Amortization		$ (121,022)		$ (62,573)

[1] Additions to intangible assets are related to the acquisition of Fraternity Community Bancorp, Inc.

[2] Additions to intangibles are related to the acquisition of Fairmount Bancorp, Inc.