Statements of Changes in Stockholders' Equity - USD ($)	Common Stock [Member]	Capital in Excess of Par Value [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Unearned ESOP Shares [Member]	Total
Balance, beginning at Jun. 30, 2017	$ 1,009,958	$ 17,650,335	$ (3,599)	$ 21,670,196	$ (7,779,099)	$ (650,248)	$ 31,897,543
Balance, beginning, shares at Jun. 30, 2017	2,371,321				658,553		2,371,321
Net income				2,375,399			$ 2,375,399
Other comprehensive loss, net of tax			(2,993)				(2,993)
Total comprehensive income							2,372,406
Stock options exercised		124,036			$ 77,550		201,586
Stock options exercised, shares	9,400				(9,400)
Stock-based compensation		86,675					86,675
Dividends paid on common stock				(1,744,062)			(1,744,062)
Purchase of treasury stock					$ (109,694)		(109,694)
Purchase of treasury stock, shares	(4,798)				4,798
Balance, ending at Mar. 31, 2018	$ 1,009,958	17,861,046	(6,592)	22,301,533	$ (7,811,243)	(650,248)	32,704,454
Balance, ending, common shares at Mar. 31, 2018	2,375,923				653,951
Balance, beginning at Jun. 30, 2017	$ 1,009,958	17,650,335	(3,599)	21,670,196	$ (7,779,099)	(650,248)	$ 31,897,543
Balance, beginning, shares at Jun. 30, 2017	2,371,321				658,553		2,371,321
Stock options exercised, shares							20,601
Balance, ending at Jun. 30, 2018	$ 1,009,958	18,201,691	(6,349)	22,416,400	$ (7,718,835)	(421,453)	$ 33,481,412
Balance, ending, common shares at Jun. 30, 2018	2,387,124				642,750		2,387,124
Balance, beginning at Dec. 31, 2017	$ 1,009,958	17,700,805	(4,449)	22,565,450	$ (7,888,793)	(650,248)	$ 32,732,723
Balance, beginning, shares at Dec. 31, 2017	2,366,523				663,351
Net income				317,764			317,764
Other comprehensive loss, net of tax			(2,143)				(2,143)
Total comprehensive income							315,621
Stock options exercised		124,036			$ 77,550		201,586
Stock options exercised, shares	9,400				(9,400)
Stock-based compensation		36,205					36,205
Dividends paid on common stock				(581,681)			(581,681)
Balance, ending at Mar. 31, 2018	$ 1,009,958	17,861,046	(6,592)	22,301,533	$ (7,811,243)	(650,248)	32,704,454
Balance, ending, common shares at Mar. 31, 2018	2,375,923				653,951
Balance, beginning at Jun. 30, 2018	$ 1,009,958	18,201,691	(6,349)	22,416,400	$ (7,718,835)	(421,453)	$ 33,481,412
Balance, beginning, shares at Jun. 30, 2018	2,387,124				642,750		2,387,124
Net income				1,201,886			$ 1,201,886
Other comprehensive loss, net of tax			3,766				3,766
Total comprehensive income							1,205,652
Stock options exercised		179,039			$ 127,042		$ 306,081
Stock options exercised, shares	15,399				(15,399)		15,399
Stock-based compensation		124,972					$ 124,972
Dividends paid on common stock				(4,144,075)			(4,144,075)
Balance, ending at Mar. 31, 2019	$ 1,009,958	18,505,702	(2,583)	19,474,211	$ (7,591,793)	(421,453)	$ 30,974,042
Balance, ending, common shares at Mar. 31, 2019	2,402,523				627,351		2,402,523
Balance, beginning at Dec. 31, 2018	$ 1,009,958	18,403,798	(4,095)	19,145,095	$ (7,642,943)	(421,453)	$ 30,490,360
Balance, beginning, shares at Dec. 31, 2018	2,396,323				633,551
Net income				922,456			922,456
Other comprehensive loss, net of tax			1,512				1,512
Total comprehensive income							923,968
Stock options exercised		54,808			$ 51,150		105,958
Stock options exercised, shares	6,200				(6,200)
Stock-based compensation		47,096					47,096
Dividends paid on common stock				(593,340)			(593,340)
Balance, ending at Mar. 31, 2019	$ 1,009,958	$ 18,505,702	$ (2,583)	$ 19,474,211	$ (7,591,793)	$ (421,453)	$ 30,974,042
Balance, ending, common shares at Mar. 31, 2019	2,402,523				627,351		2,402,523