Condensed Consolidated Financial Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance (in shares) at Jun. 30, 2020	29,680,843			34,900
Balance at Jun. 30, 2020	$ 59	$ 50,263	$ (44,156)	$ (99)	$ 6,067
Stock compensation expense for employee stock options	0	8	0	0	8
Net income	0	0	1,041	0	1,041
Net income	$ 0	0	1,041	$ 0	1,041
Balance (in shares) at Sep. 30, 2020	29,680,843			34,900
Balance at Sep. 30, 2020	$ 59	50,271	(43,115)	$ (99)	7,116
Balance (in shares) at Jun. 30, 2020	29,680,843			34,900
Balance at Jun. 30, 2020	$ 59	50,263	(44,156)	$ (99)	6,067
Net income					2,265
Net income					2,265
Balance (in shares) at Dec. 31, 2020	29,715,843			34,900
Balance at Dec. 31, 2020	$ 59	50,364	(41,891)	$ (99)	8,433
Balance (in shares) at Sep. 30, 2020	29,680,843			34,900
Balance at Sep. 30, 2020	$ 59	50,271	(43,115)	$ (99)	7,116
Stock compensation expense for employee stock options	$ 0	86	0	$ 0	86
Shares issued upon exercise of employee stock options (in shares)	35,000			0
Shares issued upon exercise of employee stock options	$ 0	7	0	$ 0	7
Net income	0	0	1,224	0	1,224
Net income	$ 0	0	1,224	$ 0	1,224
Balance (in shares) at Dec. 31, 2020	29,715,843			34,900
Balance at Dec. 31, 2020	$ 59	50,364	(41,891)	$ (99)	8,433
Balance (in shares) at Jun. 30, 2021	29,838,177			34,900
Balance at Jun. 30, 2021	$ 60	50,516	(36,143)	$ (99)	14,334
Stock compensation expense for employee stock options	$ 0	37	0	$ 0	37
Shares issued upon exercise of employee stock options (in shares)	17,000			0
Shares issued upon exercise of employee stock options	$ 0	4	0	$ 0	4
Net income	0	0	516	0	516
Net income	$ 0	0	516	$ 0	516
Balance (in shares) at Sep. 30, 2021	29,855,177			34,900
Balance at Sep. 30, 2021	$ 60	50,557	(35,627)	$ (99)	14,891
Balance (in shares) at Jun. 30, 2021	29,838,177			34,900
Balance at Jun. 30, 2021	$ 60	50,516	(36,143)	$ (99)	$ 14,334
Shares issued upon exercise of employee stock options (in shares)					28,667
Net income					$ 1,547
Net income					1,547
Balance (in shares) at Dec. 31, 2021	29,866,844			34,900
Balance at Dec. 31, 2021	$ 60	50,705	(34,596)	$ (99)	16,070
Balance (in shares) at Sep. 30, 2021	29,855,177			34,900
Balance at Sep. 30, 2021	$ 60	50,557	(35,627)	$ (99)	14,891
Stock compensation expense for employee stock options	$ 0	145	0	$ 0	145
Shares issued upon exercise of employee stock options (in shares)	11,667			0
Shares issued upon exercise of employee stock options	$ 0	3	0	$ 0	3
Net income	0	0	1,031	0	1,031
Net income	$ 0	0	1,031	$ 0	1,031
Balance (in shares) at Dec. 31, 2021	29,866,844			34,900
Balance at Dec. 31, 2021	$ 60	$ 50,705	$ (34,596)	$ (99)	$ 16,070