Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Current Assets:
Cash and cash equivalents	$ 13,331	$ 24,739
Restricted cash	25	25
Marketable securities	5,956	0
Ownership interests	860	4,549
Prepaid expenses and other current assets	1,251	965
Total current assets	21,423	30,278
Right-of-use asset, net	1,290	1,561
Ownership interests and advances	14,545	21,972
Other assets	434	217
Total Assets	37,692	54,028
Current Liabilities:
Accounts payable	16	41
Accrued compensation and benefits	507	794
Accrued expenses and other current liabilities	865	524
Lease liability - current	429	375
Total current liabilities	1,817	1,734
Lease liability - non-current	1,249	1,678
Other long-term liabilities	50	50
Total Liabilities	3,116	3,462
Commitments and contingencies (Note 11)
Equity:
Preferred stock, $0.10 par value; 1,000 shares authorized	0	0
Common stock, $0.10 par value; 83,333 shares authorized; 21,573 issued at December 31, 2022 and 2021, respectively	2,157	2,157
Additional paid-in capital	804,752	806,638
Treasury stock, at cost; 5,478 and 5,068 shares at December 31, 2022 and 2021, respectively	(48,410)	(48,569)
Accumulated deficit	(723,898)	(709,635)
Accumulated other comprehensive loss	(25)	(25)
Total Equity	34,576	50,566
Total Liabilities and Equity	$ 37,692	$ 54,028