Note 6 - Loans Receivable and Allowance for Loan Losses - Balances of Classified Loans Based On Risk Grade (Details) - USD ($)		Jun. 30, 2017		Mar. 31, 2017		Jun. 30, 2016
Loans Receivable		$ 353,731,904		$ 338,999,832
Legacy Loans [Member]
Loans Receivable		229,776,396	[1]	209,897,546	[1]	$ 177,451,686
Acquired Loans [Member]
Loans Receivable		123,955,508		129,102,286		154,884,965
Pass [Member]
Loans Receivable		339,640,764		324,151,352
Pass [Member] | Legacy Loans [Member]
Loans Receivable		219,965,137		200,026,200
Pass [Member] | Acquired Loans [Member]
Loans Receivable		119,675,627		124,125,152
Special Mention [Member]
Loans Receivable		10,650,918		11,401,812
Special Mention [Member] | Legacy Loans [Member]
Loans Receivable		7,781,166		7,828,565
Special Mention [Member] | Acquired Loans [Member]
Loans Receivable		2,869,752		3,573,247
Substandard [Member]
Loans Receivable		3,440,222		3,446,668
Substandard [Member] | Legacy Loans [Member]
Loans Receivable		2,030,093		2,042,781
Substandard [Member] | Acquired Loans [Member]
Loans Receivable		1,410,129		1,403,887
Doubtful [Member]
Loans Receivable
Doubtful [Member] | Legacy Loans [Member]
Loans Receivable
Doubtful [Member] | Acquired Loans [Member]
Loans Receivable
Unlikely to be Collected Financing Receivable [Member]
Loans Receivable
Unlikely to be Collected Financing Receivable [Member] | Legacy Loans [Member]
Loans Receivable
Unlikely to be Collected Financing Receivable [Member] | Acquired Loans [Member]
Loans Receivable
Real Estate Loans [Member]
Loans Receivable		292,505,956		293,721,660
Real Estate Loans [Member] | Legacy Loans [Member]
Loans Receivable	[1]	178,185,097		174,842,452
Real Estate Loans [Member] | Acquired Loans [Member]
Loans Receivable		114,320,859		118,879,208
Real Estate Loans [Member] | Residential [Member] | Legacy Loans [Member]
Loans Receivable		75,418,756				50,967,086
Real Estate Loans [Member] | Residential [Member] | Acquired Loans [Member]
Loans Receivable		80,296,553				98,544,840
Real Estate Loans [Member] | Residential [Member] | Pass [Member]
Loans Receivable		151,773,575		152,949,798
Real Estate Loans [Member] | Residential [Member] | Pass [Member] | Legacy Loans [Member]
Loans Receivable		73,580,895		71,721,341
Real Estate Loans [Member] | Residential [Member] | Pass [Member] | Acquired Loans [Member]
Loans Receivable		78,192,680		81,228,457
Real Estate Loans [Member] | Residential [Member] | Special Mention [Member]
Loans Receivable		2,605,638		3,224,423
Real Estate Loans [Member] | Residential [Member] | Special Mention [Member] | Legacy Loans [Member]
Loans Receivable		1,486,142		1,499,436
Real Estate Loans [Member] | Residential [Member] | Special Mention [Member] | Acquired Loans [Member]
Loans Receivable		1,119,496		1,724,987
Real Estate Loans [Member] | Residential [Member] | Substandard [Member]
Loans Receivable		1,336,095		1,270,921
Real Estate Loans [Member] | Residential [Member] | Substandard [Member] | Legacy Loans [Member]
Loans Receivable		351,718		331,976
Real Estate Loans [Member] | Residential [Member] | Substandard [Member] | Acquired Loans [Member]
Loans Receivable		984,377		938,945
Real Estate Loans [Member] | Investor Loans [Member] | Legacy Loans [Member]
Loans Receivable		7,811,461				11,825,434
Real Estate Loans [Member] | Investor Loans [Member] | Acquired Loans [Member]
Loans Receivable		18,433,397				23,606,757
Real Estate Loans [Member] | Investor Loans [Member] | Pass [Member]
Loans Receivable		25,727,935		24,880,026
Real Estate Loans [Member] | Investor Loans [Member] | Pass [Member] | Legacy Loans [Member]
Loans Receivable		7,803,689		6,728,493
Real Estate Loans [Member] | Investor Loans [Member] | Pass [Member] | Acquired Loans [Member]
Loans Receivable		17,924,246		18,151,533
Real Estate Loans [Member] | Investor Loans [Member] | Special Mention [Member]
Loans Receivable		325,422		408,803
Real Estate Loans [Member] | Investor Loans [Member] | Special Mention [Member] | Legacy Loans [Member]
Loans Receivable
Real Estate Loans [Member] | Investor Loans [Member] | Special Mention [Member] | Acquired Loans [Member]
Loans Receivable		325,422		408,803
Real Estate Loans [Member] | Investor Loans [Member] | Substandard [Member]
Loans Receivable		191,500		233,284
Real Estate Loans [Member] | Investor Loans [Member] | Substandard [Member] | Legacy Loans [Member]
Loans Receivable		7,772		13,976
Real Estate Loans [Member] | Investor Loans [Member] | Substandard [Member] | Acquired Loans [Member]
Loans Receivable		183,728		219,308
Real Estate Loans [Member] | Commercial [Member]
Loans Receivable		107,027,825		107,564,212
Real Estate Loans [Member] | Commercial [Member] | Legacy Loans [Member]
Loans Receivable		92,628,423	[1],[2]	92,665,689	[1]	81,155,633
Real Estate Loans [Member] | Commercial [Member] | Acquired Loans [Member]
Loans Receivable		14,399,402		14,898,523		17,875,858
Real Estate Loans [Member] | Commercial [Member] | Pass [Member]
Loans Receivable		97,687,449		98,177,735
Real Estate Loans [Member] | Commercial [Member] | Pass [Member] | Legacy Loans [Member]
Loans Receivable		84,786,588		84,789,748
Real Estate Loans [Member] | Commercial [Member] | Pass [Member] | Acquired Loans [Member]
Loans Receivable		12,900,861		13,387,987
Real Estate Loans [Member] | Commercial [Member] | Special Mention [Member]
Loans Receivable		7,590,351		7,634,821
Real Estate Loans [Member] | Commercial [Member] | Special Mention [Member] | Legacy Loans [Member]
Loans Receivable		6,295,024		6,329,129
Real Estate Loans [Member] | Commercial [Member] | Special Mention [Member] | Acquired Loans [Member]
Loans Receivable		1,295,327		1,305,692
Real Estate Loans [Member] | Commercial [Member] | Substandard [Member]
Loans Receivable		1,750,027		1,751,656
Real Estate Loans [Member] | Commercial [Member] | Substandard [Member] | Legacy Loans [Member]
Loans Receivable		1,546,812		1,546,812
Real Estate Loans [Member] | Commercial [Member] | Substandard [Member] | Acquired Loans [Member]
Loans Receivable		203,215		204,844
Real Estate Loans [Member] | Commercial construction [Member]
Loans Receivable		3,517,964		3,190,193
Real Estate Loans [Member] | Commercial construction [Member] | Legacy Loans [Member]
Loans Receivable		2,326,457	[1]	1,881,541	[1]	2,348,741
Real Estate Loans [Member] | Commercial construction [Member] | Acquired Loans [Member]
Loans Receivable		1,191,507		1,308,652		1,615,922
Real Estate Loans [Member] | Commercial construction [Member] | Pass [Member]
Loans Receivable		3,517,964		3,190,193
Real Estate Loans [Member] | Commercial construction [Member] | Pass [Member] | Legacy Loans [Member]
Loans Receivable		2,326,457		1,881,541
Real Estate Loans [Member] | Commercial construction [Member] | Pass [Member] | Acquired Loans [Member]
Loans Receivable		1,191,507		1,308,652
Real Estate Loans [Member] | Commercial construction [Member] | Special Mention [Member]
Loans Receivable
Real Estate Loans [Member] | Commercial construction [Member] | Special Mention [Member] | Legacy Loans [Member]
Loans Receivable
Real Estate Loans [Member] | Commercial construction [Member] | Special Mention [Member] | Acquired Loans [Member]
Loans Receivable
Real Estate Loans [Member] | Commercial construction [Member] | Substandard [Member]
Loans Receivable
Real Estate Loans [Member] | Commercial construction [Member] | Substandard [Member] | Legacy Loans [Member]
Loans Receivable
Real Estate Loans [Member] | Commercial construction [Member] | Substandard [Member] | Acquired Loans [Member]
Loans Receivable
Commercial Portfolio Segment [Member]
Loans Receivable		37,376,347		21,537,366
Commercial Portfolio Segment [Member] | Legacy Loans [Member]
Loans Receivable		35,339,083	[1]	19,518,029	[1]	15,985,673
Commercial Portfolio Segment [Member] | Acquired Loans [Member]
Loans Receivable		2,037,264		2,019,337		2,714,738
Commercial Portfolio Segment [Member] | Pass [Member]
Loans Receivable		37,263,536		21,396,100
Commercial Portfolio Segment [Member] | Pass [Member] | Legacy Loans [Member]
Loans Receivable		35,226,272		19,376,763
Commercial Portfolio Segment [Member] | Pass [Member] | Acquired Loans [Member]
Loans Receivable		2,037,264		2,019,337
Commercial Portfolio Segment [Member] | Special Mention [Member]
Loans Receivable
Commercial Portfolio Segment [Member] | Special Mention [Member] | Legacy Loans [Member]
Loans Receivable
Commercial Portfolio Segment [Member] | Special Mention [Member] | Acquired Loans [Member]
Loans Receivable
Commercial Portfolio Segment [Member] | Substandard [Member]
Loans Receivable		112,811		141,266
Commercial Portfolio Segment [Member] | Substandard [Member] | Legacy Loans [Member]
Loans Receivable		112,811		141,266
Commercial Portfolio Segment [Member] | Substandard [Member] | Acquired Loans [Member]
Loans Receivable
Home equity loans [Member]
Loans Receivable		20,785,332		20,544,370
Home equity loans [Member] | Legacy Loans [Member]
Loans Receivable		14,116,647	[1]	13,278,229	[1]	12,293,585
Home equity loans [Member] | Acquired Loans [Member]
Loans Receivable		6,668,685		7,266,141		9,495,334
Home equity loans [Member] | Pass [Member]
Loans Receivable		20,644,845		20,402,642
Home equity loans [Member] | Pass [Member] | Legacy Loans [Member]
Loans Receivable		14,105,667		13,269,478
Home equity loans [Member] | Pass [Member] | Acquired Loans [Member]
Loans Receivable		6,539,178		7,133,164
Home equity loans [Member] | Special Mention [Member]
Loans Receivable		129,507		132,977
Home equity loans [Member] | Special Mention [Member] | Legacy Loans [Member]
Loans Receivable
Home equity loans [Member] | Special Mention [Member] | Acquired Loans [Member]
Loans Receivable		129,507		132,977
Home equity loans [Member] | Substandard [Member]
Loans Receivable		10,980		8,751
Home equity loans [Member] | Substandard [Member] | Legacy Loans [Member]
Loans Receivable		10,980		8,751
Home equity loans [Member] | Substandard [Member] | Acquired Loans [Member]
Loans Receivable
Consumer Portfolio Segment [Member]
Loans Receivable		3,064,269		3,196,436
Consumer Portfolio Segment [Member] | Legacy Loans [Member]
Loans Receivable		2,135,569	[1]	2,258,836	[1]	2,875,534
Consumer Portfolio Segment [Member] | Acquired Loans [Member]
Loans Receivable		928,700		937,600		$ 1,031,516
Consumer Portfolio Segment [Member] | Pass [Member]
Loans Receivable		3,025,460		3,154,858
Consumer Portfolio Segment [Member] | Pass [Member] | Legacy Loans [Member]
Loans Receivable		2,135,569		2,258,836
Consumer Portfolio Segment [Member] | Pass [Member] | Acquired Loans [Member]
Loans Receivable		889,891		896,022
Consumer Portfolio Segment [Member] | Special Mention [Member]
Loans Receivable				788
Consumer Portfolio Segment [Member] | Special Mention [Member] | Legacy Loans [Member]
Loans Receivable
Consumer Portfolio Segment [Member] | Special Mention [Member] | Acquired Loans [Member]
Loans Receivable				788
Consumer Portfolio Segment [Member] | Substandard [Member]
Loans Receivable		38,809		40,790
Consumer Portfolio Segment [Member] | Substandard [Member] | Legacy Loans [Member]
Loans Receivable
Consumer Portfolio Segment [Member] | Substandard [Member] | Acquired Loans [Member]
Loans Receivable		$ 38,809		$ 40,790

[1] As a result of the acquisition of Fraternity Community Bancorp, Inc., the parent company of Fraternity Federal Savings and Loan, in May 2016 and Fairmount Bancorp, Inc., the parent company of Fairmount Bank, in September 2015, we have segmented the portfolio into two components, loans originated by Hamilton Bank "Legacy" and loans acquired from Fraternity Community Bancorp, Inc. and Fairmount Bancorp, Inc. "Acquired".

[2] "Legacy" commercial business loans at June 30, 2017 includes $15.4 million of loans purchased in June 2017.