Long-Term Debt (Details) - 2012 Note - 8¼% Limited Convertible Senior Subordinated Notes Due 2012 [Member] - USD ($)		3 Months Ended
	Jan. 15, 2021	Mar. 31, 2021	Dec. 31, 2020
Long-Term Debt (Details) - 2012 Note [Line Items]
Long-term Debt		$ 302,000	$ 352,000
Debt Instrument, Maturity Date		Mar. 01, 2012
Interest Payable, Current		$ 289,000	$ 329,000
Debt Instrument, Face Amount	$ 50,000
Debt Exchange Each Principal Amount Of Original Debt Exchanged	1,000
Repayment Of Convertible Debt Principal	400
Debt Exchanged Aggregate Payment	$ 20,000
Gain (Loss) on Extinguishment of Debt		$ 77,000