Note 3 - Acquisitions - Pro Forma Condensed Combined Financial Information (Details) - USD ($)	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Fraternity Community Bancorp, Inc. [Member]
Other non-interest revenue	$ 1,076,971	$ 1,733,401
Total revenue	15,561,648	16,119,031
Provision expense	3,395,006	440,000
Other non-interest expense	12,378,437	14,584,149
(Loss) income before income taxes	(211,795)	1,094,882
Income tax (benefit) expense	(239,925)	717,693
Net income	$ 28,130	$ 377,189
Basic (loss) earnings per share (in dollars per share)	$ 0.01	$ 0.12
Basic earnings per share (in dollars per share)	0.01	0.12
Diluted earnings per share (in dollars per share)	$ 0.01	$ 0.12
Net interest income	$ 14,484,677	$ 14,385,630
Fairmount Bancorp, Inc. [Member]
Other non-interest revenue	1,054,547	1,657,715
Total revenue	14,945,047	12,606,236
Provision expense	3,395,006	440,000
Other non-interest expense	13,236,828	10,462,955
(Loss) income before income taxes	(1,686,787)	1,703,281
Income tax (benefit) expense	(758,005)	840,532
Net income	$ (928,782)	$ 862,749
Basic (loss) earnings per share (in dollars per share)	$ (0.29)	$ 0.27
Basic earnings per share (in dollars per share)	(0.29)	0.27
Diluted earnings per share (in dollars per share)	$ (0.29)	$ 0.27
Net interest income	$ 13,890,500	$ 10,948,521