CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	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, 2018	$ 91	$ 210,083	$ (151,795)	$ (2,313)		$ 56,066
Balance (in shares) at Jun. 30, 2018	9,117,077
Share-based compensation expense		74				74
Repurchase and retirement of stock	$ (1)	(613)				(614)
Repurchase and retirement of stock (in shares)	(156,423)
Lapse of restrictions on restricted stock (in shares)	7,500
Adoption of ASU 2016-01			318	(318)
Other comprehensive income, net of taxes:
Net income (loss)			(1,533)			(1,533)
Unrealized loss on available-for-sale investments				(2,690)		(2,690)
Foreign currency translation adjustment				76		76
Pension and post-retirement benefits, net of tax				32		32
Total comprehensive income						(4,115)
Balance at Dec. 31, 2018	$ 90	209,544	(153,010)	(5,213)		51,411
Balance (in shares) at Dec. 31, 2018	8,968,154
Balance at Sep. 30, 2018	$ 91	210,027	(151,480)	(3,469)		55,169
Balance (in shares) at Sep. 30, 2018	9,094,069
Share-based compensation expense		16				16
Repurchase and retirement of stock	$ (1)	(499)				(500)
Repurchase and retirement of stock (in shares)	(133,415)
Other comprehensive income, net of taxes:
Net income (loss)			(1,530)			(1,530)
Unrealized loss on available-for-sale investments				(1,813)		(1,813)
Foreign currency translation adjustment				53		53
Pension and post-retirement benefits, net of tax				16		16
Total comprehensive income						(3,274)
Balance at Dec. 31, 2018	$ 90	209,544	(153,010)	(5,213)		51,411
Balance (in shares) at Dec. 31, 2018	8,968,154
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 income, net of taxes:
Net income (loss)			6,143		452	6,595
Unrealized loss on available-for-sale investments				(1,609)		(1,609)
Foreign currency translation adjustment				56		56
Pension and post-retirement benefits, net of tax				44		44
Total comprehensive income						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 income, net of taxes:
Net income (loss)			2,737		297	3,034
Unrealized loss on available-for-sale investments				(1,438)		(1,438)
Foreign currency translation adjustment				(42)		(42)
Pension and post-retirement benefits, net of tax				(46)		(46)
Total comprehensive income						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