Note 13 - Fair Value Measurements (Details Textual) - USD ($)		Sep. 30, 2017	Mar. 31, 2017	Sep. 30, 2016
Impaired Financing Receivable, Recorded Investment	[1]	$ 8,859,798	$ 5,657,048	$ 7,026,359
Real Estate Acquired Through Foreclosure		483,204	503,094
Fraternity Community Bancorp, Inc. [Member]
Assets Held-for-sale, Not Part of Disposal Group, Current		547,884	547,884
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired Financing Receivable, Recorded Investment		8,859,798	5,657,048
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		270,329	285,359
Real Estate Acquired Through Foreclosure		$ 483,204	$ 503,094

[1] Generally accepted accounting principles require that we record acquired loans at fair value at acquisition, which includes a discount for loans with credit impairment. These purchased credit impaired loans are not performing according to their contractual terms and meet the definition of an impaired loan. Although we do not accrue interest income at the contractual rate on these loans, we do recognize an accretable yield as interest income to the extent such yield is supported by cash flow analysis of the underlying loans.