CONSOLIDATED STATEMENT OF STOCKHOLDERS EQUITY - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Total
BALANCE at Jun. 30, 2018	$ 212,000	$ 16,890,000	$ (13,069,000)	$ 59,420,000	$ 63,453,000
BALANCE (in shares) at Jun. 30, 2018	21,204,327		(2,475,245)
Net income	$ 0	0	$ 0	1,504,000	1,504,000
Implementation of ASC606	0	0	0	(719,000)	(719,000)
Repurchase of treasury shares	$ 0	0	$ (549,000)	0	(549,000)
Repurchase of treasury shares (in shares)	0		(39,163)
Stock options exercised	$ 0	15,000	$ 0	0	15,000
Stock options exercised (in shares)	2,500		0
Stock-based compensation expense	$ 0	5,000	$ 0	0	5,000
BALANCE at Sep. 30, 2018	$ 212,000	16,910,000	$ (13,618,000)	60,205,000	63,709,000
BALANCE (in shares) at Sep. 30, 2018	21,206,827		(2,514,408)
BALANCE at Jun. 30, 2018	$ 212,000	16,890,000	$ (13,069,000)	59,420,000	63,453,000
BALANCE (in shares) at Jun. 30, 2018	21,204,327		(2,475,245)
Net income					4,373,000
BALANCE at Dec. 31, 2018	$ 212,000	17,066,000	$ (15,707,000)	63,074,000	64,645,000
BALANCE (in shares) at Dec. 31, 2018	21,219,342		(2,661,638)
BALANCE at Sep. 30, 2018	$ 212,000	16,910,000	$ (13,618,000)	60,205,000	63,709,000
BALANCE (in shares) at Sep. 30, 2018	21,206,827		(2,514,408)
Net income	$ 0	0	$ 0	2,869,000	2,869,000
Repurchase of treasury shares	0	0	$ (2,089,000)	0	(2,089,000)
Repurchase of treasury shares (in shares)			(147,230)
Stock options exercised	$ 0	9,000	$ 0	0	9,000
Stock options exercised (in shares)	12,515		0
Stock-based compensation expense	$ 0	147,000	$ 0	0	147,000
BALANCE at Dec. 31, 2018	$ 212,000	17,066,000	$ (15,707,000)	63,074,000	64,645,000
BALANCE (in shares) at Dec. 31, 2018	21,219,342		(2,661,638)
BALANCE at Jun. 30, 2019	$ 212,000	17,103,000	$ (17,067,000)	70,924,000	71,172,000
BALANCE (in shares) at Jun. 30, 2019	21,227,094		(2,749,310)
Net income	$ 0	0	$ 0	3,233,000	3,233,000
Stock-based compensation expense	0	17,000	0	0	17,000
BALANCE at Sep. 30, 2019	$ 212,000	17,120,000	$ (17,067,000)	74,157,000	74,422,000
BALANCE (in shares) at Sep. 30, 2019	21,227,094		(2,749,310)
BALANCE at Jun. 30, 2019	$ 212,000	17,103,000	$ (17,067,000)	70,924,000	71,172,000
BALANCE (in shares) at Jun. 30, 2019	21,227,094		(2,749,310)
Net income					6,805,000
BALANCE at Dec. 31, 2019	$ 212,000	17,428,000	$ (17,067,000)	77,729,000	78,302,000
BALANCE (in shares) at Dec. 31, 2019	21,227,094		(2,749,310)
BALANCE at Sep. 30, 2019	$ 212,000	17,120,000	$ (17,067,000)	74,157,000	74,422,000
BALANCE (in shares) at Sep. 30, 2019	21,227,094		(2,749,310)
Net income	$ 0	0	$ 0	3,572,000	3,572,000
Stock-based compensation expense	0	308,000	0	0	308,000
BALANCE at Dec. 31, 2019	$ 212,000	$ 17,428,000	$ (17,067,000)	$ 77,729,000	$ 78,302,000
BALANCE (in shares) at Dec. 31, 2019	21,227,094		(2,749,310)