CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)
Balance at beginning (in shares) at Jun. 30, 2019		16,433,128	(295,615,000)
Balances at beginning at Jun. 30, 2019	$ 26,126	$ 165	$ (1,554)	$ 29,020	$ (1,505)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	134,194	134,194
Exercise of stock options	$ 576	$ 1		575
Stock-based compensation	372			372
Issuance of restricted stock (in shares)		72,000
Issuance of restricted stock	0	$ 1		(1)
Net income (loss)	100				100
Balance at end (in shares) at Mar. 31, 2020		16,639,322	(295,615,000)
Balances at end at Mar. 31, 2020	27,174	$ 167	$ (1,554)	29,966	(1,405)
Balance at beginning (in shares) at Dec. 31, 2019		16,524,478	(295,615,000)
Balances at beginning at Dec. 31, 2019	$ 28,065	$ 166	$ (1,554)	29,302	151
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	114,844	114,844
Exercise of stock options	$ 518	$ 1		517
Stock-based compensation	147			147
Net income (loss)	(1,556)				(1,556)
Balance at end (in shares) at Mar. 31, 2020		16,639,322	(295,615,000)
Balances at end at Mar. 31, 2020	27,174	$ 167	$ (1,554)	29,966	(1,405)
Balance at beginning (in shares) at Jun. 30, 2020		16,667,572	(295,615,000)
Balances at beginning at Jun. 30, 2020	$ 29,578	$ 168	$ (1,554)	30,203	761
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	141,281	141,281
Exercise of stock options	$ 625	$ 2		623
Stock-based compensation	832			832
Issuance of restricted stock (in shares)		73,180
Issuance of restricted stock	0	$ 1		(1)
Net income (loss)	7,785				7,785
Balance at end (in shares) at Mar. 31, 2021		16,882,033	(295,615,000)
Balances at end at Mar. 31, 2021	38,820	$ 171	$ (1,554)	31,657	8,546
Balance at beginning (in shares) at Dec. 31, 2020		16,799,702	(295,615,000)
Balances at beginning at Dec. 31, 2020	$ 31,126	$ 170	$ (1,554)	30,814	1,696
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	72,750	72,750
Exercise of stock options	$ 314	$ 1		313
Stock-based compensation	530			530
Issuance of restricted stock (in shares)		9,581
Issuance of restricted stock	0	$ 0		0
Net income (loss)	6,850				6,850
Balance at end (in shares) at Mar. 31, 2021		16,882,033	(295,615,000)
Balances at end at Mar. 31, 2021	$ 38,820	$ 171	$ (1,554)	$ 31,657	$ 8,546