Note 7 - Goodwill and Other Intangible Asset - Activity in Goodwill and Acquired Intangible Assets Related to Branch Purchase (Details) - USD ($)		3 Months Ended
		Jun. 30, 2017	Jun. 30, 2016
Goodwill, Beginning Balance		$ 8,563,530	$ 6,767,811
Goodwill, Additions	[1]		3,147,441
Goodwill, Post acquisition adjustments			(93,226)
Goodwill, Ending Balance		8,563,530	9,822,026
Core deposit intangible, Amortization		(31,516)	(26,474)
Core deposit intangible, Ending Balance		707,782
Core Deposits [Member]
Core deposit intangible, Beginning Balance		739,298	618,300
Core deposit intangible, Additions	[1]		242,020
Core deposit intangible, Post acquisition adjustments
Core deposit intangible, Amortization		(31,516)	(26,473)
Core deposit intangible, Ending Balance		$ 707,782	$ 833,847

[1] Additions to intangible assets are related to acquisition of Fraternity Community.