CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common stock and common stock options	Capital In Excess Of Par Value [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-Controlling Interest [Member]	Total
Balance at Jun. 30, 2019	$ 87	$ 208,881	$ (150,795)	$ (6,579)	$ 762	$ 52,356
Balance (in shares) at Jun. 30, 2019	8,756,156
Share-based compensation expense		195				195
Lapse of restrictions on restricted stock (in shares)	5,000
Other comprehensive (loss) income, net of taxes:
Net income (loss)			6,143		452	6,595
Unrealized gain (loss) on available-for-sale investments				(1,609)		(1,609)
Foreign currency translation adjustment				56		56
Pension plan				44		44
Total comprehensive income (loss)						5,086
Balance at Dec. 31, 2019	$ 87	209,076	(144,652)	(8,088)	1,214	57,637
Balance (in shares) at Dec. 31, 2019	8,761,156
Balance at Sep. 30, 2019	$ 87	208,980	(147,389)	(6,562)	917	56,033
Balance (in shares) at Sep. 30, 2019	8,756,156
Share-based compensation expense		96				96
Lapse of restrictions on restricted stock (in shares)	5,000
Other comprehensive (loss) income, net of taxes:
Net income (loss)			2,737		297	3,034
Unrealized gain (loss) on available-for-sale investments				(1,438)		(1,438)
Foreign currency translation adjustment				(42)		(42)
Pension plan				(46)		(46)
Total comprehensive income (loss)						1,508
Balance at Dec. 31, 2019	$ 87	209,076	(144,652)	(8,088)	1,214	57,637
Balance (in shares) at Dec. 31, 2019	8,761,156
Balance at Jun. 30, 2020	$ 88	209,223	(143,077)	(6,206)	1,261	61,289
Balance (in shares) at Jun. 30, 2020	8,797,671
Share-based compensation expense		292				292
Lapse of restrictions on restricted stock (in shares)	41,673
Forfeitures of restricted stock		(227)				(227)
Forfeitures of stock options		(12)				(12)
Dividends forfeited with restricted stock forfeitures			43			43
Distributions to non-controlling interest					(59)	(59)
Other comprehensive (loss) income, net of taxes:
Net income (loss)			(7,944)		(23)	(7,967)
Unrealized gain (loss) on available-for-sale investments				3,236		3,236
Foreign currency translation adjustment				(241)		(241)
Pension plan				(94)		(94)
Total comprehensive income (loss)						(5,066)
Balance at Dec. 31, 2020	$ 88	209,276	(150,978)	(3,305)	1,179	56,260
Balance (in shares) at Dec. 31, 2020	8,839,344
Balance at Sep. 30, 2020	$ 88	209,283	(142,674)	(7,093)	1,224	60,828
Balance (in shares) at Sep. 30, 2020	8,797,671
Share-based compensation expense		166				166
Lapse of restrictions on restricted stock (in shares)	41,673
Forfeitures of restricted stock		(161)				(161)
Forfeitures of stock options		(12)				(12)
Dividends forfeited with restricted stock forfeitures			29			29
Distributions to non-controlling interest					(44)	(44)
Other comprehensive (loss) income, net of taxes:
Net income (loss)			(8,333)		(1)	(8,334)
Unrealized gain (loss) on available-for-sale investments				3,964		3,964
Foreign currency translation adjustment				(127)		(127)
Pension plan				(49)		(49)
Total comprehensive income (loss)						(4,546)
Balance at Dec. 31, 2020	$ 88	$ 209,276	$ (150,978)	$ (3,305)	$ 1,179	$ 56,260
Balance (in shares) at Dec. 31, 2020	8,839,344