Income Taxes - Net deferred tax assets (Details) - USD ($)	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Gross deferred tax assets:
Allowance for loan losses	$ 1,208,020	$ 1,001,980
Net operating loss carryover		530,899
General business credits	324,364	324,364
Foreclosed asset writedowns	50,592	50,592
Unrealized loss on securities	6,393
Other	50,760	245,290
Total gross deferred tax assets	1,640,129	2,153,125
Gross deferred tax liabilities:
Additions in excess of base year loan reserve	(572,404)	(585,334)
Depreciation	(73,623)	(68,425)
FHLB stock dividends	(74,630)	(77,656)
Unrealized gain on securities		(2,100)
Other	(57,463)	(3,517)
Total gross deferred tax liabilities	(778,120)	(737,032)
Net deferred tax asset	862,009	1,416,093
Income tax uncertainties:
Adjustment for unrecognized income tax benefits	0	0
Income tax examination, interest and penalties expense:
Interest and penalties expense	0	0
Income tax examination, interest and penalties accrued:
Interest and penalties accrued	$ 0	$ 0