Condensed Consolidated Statements of Shareholders' Deficit (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2019	$ 1,123	$ 746,112	$ (819,294)	$ (72,059)
Compensation recognized under stock compensation plans		127		127
Net loss			(7,926)	(7,926)
Issuances of nonvested stock	23	(23)
Balance at Sep. 30, 2020	1,146	746,216	(827,220)	(79,858)
Balance at Jun. 30, 2020	1,146	746,170	(826,261)	(78,945)
Compensation recognized under stock compensation plans		46		46
Net loss			(959)	(959)
Balance at Sep. 30, 2020	1,146	746,216	(827,220)	(79,858)
Balance at Dec. 31, 2020	1,146	746,227	(828,463)	(81,090)
Issuances and cancellations of nonvested stock	15	(15)
Compensation recognized under stock compensation plans		115		115
Net loss			(4,051)	(4,051)
Balance at Sep. 30, 2021	1,161	746,327	(832,514)	(85,026)
Balance at Jun. 30, 2021	1,166	746,291	(831,136)	(83,679)
Compensation recognized under stock compensation plans		31		31
Net loss			(1,378)	(1,378)
Cancellations of nonvested stock	(5)	5
Balance at Sep. 30, 2021	$ 1,161	$ 746,327	$ (832,514)	$ (85,026)