Note 6 - Loans Receivable and Allowance for Loan Losses - Past Due Loans, Segregated By Age and Class of Loans (Details) - USD ($)		Jun. 30, 2017		Mar. 31, 2017		Jun. 30, 2016
Current		$ 347,350,257		$ 336,098,044
Past due		4,159,464		599,853
Nonaccrual loans		2,222,183		2,301,935
Total Loans		353,731,904		338,999,832
Nonaccrual interest not accrued		52,523		182,113
Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		3,518,513		504,192
Financing Receivables, 60 to 89 Days Past Due [Member]
Past due		309,817		74,631
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due		331,134		21,030
Real Estate Loans [Member]
Total Loans		292,505,956		293,721,660
Real Estate Loans [Member] | Residential [Member]
Nonaccrual loans		637,915		675,017
Nonaccrual interest not accrued		37,903		41,637
Real Estate Loans [Member] | Residential [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		207,196		69,618
Real Estate Loans [Member] | Residential [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due		231,808		74,631
Real Estate Loans [Member] | Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Real Estate Loans [Member] | Investor Loans [Member]
Nonaccrual loans		34,811		71,107
Nonaccrual interest not accrued		14,557		30,275
Real Estate Loans [Member] | Investor Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		72,885		320,971
Real Estate Loans [Member] | Investor Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due		78,009
Real Estate Loans [Member] | Investor Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due		331,134		21,030
Real Estate Loans [Member] | Commercial [Member]
Nonaccrual loans		1,546,811		1,546,812
Total Loans		107,027,825		107,564,212
Nonaccrual interest not accrued				109,818
Real Estate Loans [Member] | Commercial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		3,160,843
Real Estate Loans [Member] | Commercial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Real Estate Loans [Member] | Commercial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Real Estate Loans [Member] | Commercial construction [Member]
Nonaccrual loans
Total Loans		3,517,964		3,190,193
Nonaccrual interest not accrued
Real Estate Loans [Member] | Commercial construction [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		73,500		113,603
Real Estate Loans [Member] | Commercial construction [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Real Estate Loans [Member] | Commercial construction [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Commercial Portfolio Segment [Member]
Nonaccrual loans
Total Loans		37,376,347		21,537,366
Nonaccrual interest not accrued
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Home equity loans [Member]
Nonaccrual loans		2,646		3,397
Total Loans		20,785,332		20,544,370
Nonaccrual interest not accrued		63		66
Home equity loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Home equity loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Home equity loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Consumer Portfolio Segment [Member]
Nonaccrual loans				5,602
Total Loans		3,064,269		3,196,436
Nonaccrual interest not accrued				317
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		4,089
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Legacy Loans [Member]
Current		224,251,862		207,328,184
Past due		3,551,111		578,823
Nonaccrual loans		1,973,423		1,990,539
Total Loans		229,776,396	[1]	209,897,546	[1]	$ 177,451,686
Nonaccrual interest not accrued		12,358		123,326
Legacy Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		3,236,835		504,192
Legacy Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due		92,545		74,631
Legacy Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due		221,731
Legacy Loans [Member] | Real Estate Loans [Member]
Total Loans	[1]	178,185,097		174,842,452
Legacy Loans [Member] | Real Estate Loans [Member] | Residential [Member]
Nonaccrual loans		416,194		426,354
Total Loans		75,418,756				50,967,086
Nonaccrual interest not accrued		6,039		6,460
Legacy Loans [Member] | Real Estate Loans [Member] | Residential [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		75,992		69,618
Legacy Loans [Member] | Real Estate Loans [Member] | Residential [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due		92,545		74,631
Legacy Loans [Member] | Real Estate Loans [Member] | Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Legacy Loans [Member] | Real Estate Loans [Member] | Investor Loans [Member]
Nonaccrual loans		7,772		13,976
Total Loans		7,811,461				11,825,434
Nonaccrual interest not accrued		6,256		6,982
Legacy Loans [Member] | Real Estate Loans [Member] | Investor Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due				320,971
Legacy Loans [Member] | Real Estate Loans [Member] | Investor Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Legacy Loans [Member] | Real Estate Loans [Member] | Investor Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due		221,731
Legacy Loans [Member] | Real Estate Loans [Member] | Commercial [Member]
Nonaccrual loans		1,546,811		1,546,812
Total Loans		92,628,423	[1],[2]	92,665,689	[1]	81,155,633
Nonaccrual interest not accrued				109,818
Legacy Loans [Member] | Real Estate Loans [Member] | Commercial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		3,160,843
Legacy Loans [Member] | Real Estate Loans [Member] | Commercial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Legacy Loans [Member] | Real Estate Loans [Member] | Commercial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Legacy Loans [Member] | Real Estate Loans [Member] | Commercial construction [Member]
Nonaccrual loans
Total Loans		2,326,457	[1]	1,881,541	[1]	2,348,741
Nonaccrual interest not accrued
Legacy Loans [Member] | Real Estate Loans [Member] | Commercial construction [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due				113,603
Legacy Loans [Member] | Real Estate Loans [Member] | Commercial construction [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Legacy Loans [Member] | Real Estate Loans [Member] | Commercial construction [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Legacy Loans [Member] | Commercial Portfolio Segment [Member]
Nonaccrual loans
Total Loans		35,339,083	[1]	19,518,029	[1]	15,985,673
Nonaccrual interest not accrued
Legacy Loans [Member] | Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Legacy Loans [Member] | Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Legacy Loans [Member] | Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Legacy Loans [Member] | Home equity loans [Member]
Nonaccrual loans		2,646		3,397
Total Loans		14,116,647	[1]	13,278,229	[1]	12,293,585
Nonaccrual interest not accrued		63		66
Legacy Loans [Member] | Home equity loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Legacy Loans [Member] | Home equity loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Legacy Loans [Member] | Home equity loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Legacy Loans [Member] | Consumer Portfolio Segment [Member]
Nonaccrual loans
Total Loans		2,135,569	[1]	2,258,836	[1]	2,875,534
Nonaccrual interest not accrued
Legacy Loans [Member] | Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Legacy Loans [Member] | Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Legacy Loans [Member] | Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Acquired Loans [Member]
Current		123,098,395		128,769,860
Past due		608,353		21,030
Nonaccrual loans		248,760		311,396
Total Loans		123,955,508		129,102,286		154,884,965
Nonaccrual interest not accrued		40,165		58,787
Acquired Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		281,678
Acquired Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due		217,272
Acquired Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due		109,403		21,030
Acquired Loans [Member] | Real Estate Loans [Member]
Total Loans		114,320,859		118,879,208
Acquired Loans [Member] | Real Estate Loans [Member] | Residential [Member]
Nonaccrual loans		221,721		248,663
Total Loans		80,296,553				98,544,840
Nonaccrual interest not accrued		31,864		35,177
Acquired Loans [Member] | Real Estate Loans [Member] | Residential [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		131,204
Acquired Loans [Member] | Real Estate Loans [Member] | Residential [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due		139,263
Acquired Loans [Member] | Real Estate Loans [Member] | Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Acquired Loans [Member] | Real Estate Loans [Member] | Investor Loans [Member]
Nonaccrual loans		27,039		57,131
Total Loans		18,433,397				23,606,757
Nonaccrual interest not accrued		8,301		23,293
Acquired Loans [Member] | Real Estate Loans [Member] | Investor Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		72,885
Acquired Loans [Member] | Real Estate Loans [Member] | Investor Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due		78,009
Acquired Loans [Member] | Real Estate Loans [Member] | Investor Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due		109,403		21,030
Acquired Loans [Member] | Real Estate Loans [Member] | Commercial [Member]
Nonaccrual loans
Total Loans		14,399,402		14,898,523		17,875,858
Nonaccrual interest not accrued
Acquired Loans [Member] | Real Estate Loans [Member] | Commercial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Acquired Loans [Member] | Real Estate Loans [Member] | Commercial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Acquired Loans [Member] | Real Estate Loans [Member] | Commercial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Acquired Loans [Member] | Real Estate Loans [Member] | Commercial construction [Member]
Nonaccrual loans
Total Loans		1,191,507		1,308,652		1,615,922
Nonaccrual interest not accrued
Acquired Loans [Member] | Real Estate Loans [Member] | Commercial construction [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		73,500
Acquired Loans [Member] | Real Estate Loans [Member] | Commercial construction [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Acquired Loans [Member] | Real Estate Loans [Member] | Commercial construction [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Acquired Loans [Member] | Commercial Portfolio Segment [Member]
Nonaccrual loans
Total Loans		2,037,264		2,019,337		2,714,738
Nonaccrual interest not accrued
Acquired Loans [Member] | Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Acquired Loans [Member] | Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Acquired Loans [Member] | Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Acquired Loans [Member] | Home equity loans [Member]
Nonaccrual loans
Total Loans		6,668,685		7,266,141		9,495,334
Nonaccrual interest not accrued
Acquired Loans [Member] | Home equity loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Acquired Loans [Member] | Home equity loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Acquired Loans [Member] | Home equity loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Acquired Loans [Member] | Consumer Portfolio Segment [Member]
Nonaccrual loans				5,602
Total Loans		928,700		937,600		$ 1,031,516
Nonaccrual interest not accrued				317
Acquired Loans [Member] | Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		4,089
Acquired Loans [Member] | Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Acquired Loans [Member] | Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due

[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.