Consolidated Balance Sheets (Current Period Unuaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 14,246	$ 13,331
Restricted cash	25	25
Marketable securities	841	5,956
Ownership interests	0	860
Prepaid expenses and other current assets	1,615	1,251
Total current assets	16,727	21,423
Right-of-use asset, net	1,136	1,290
Ownership interests and advances	12,972	14,545
Other assets	247	434
Total Assets	31,082	37,692
Current Liabilities:
Accounts payable	67	16
Accrued compensation and benefits	164	507
Accrued expenses and other current liabilities	567	865
Lease liability - current	458	429
Total current liabilities	1,256	1,817
Lease liability - non-current	1,013	1,249
Other long-term liabilities	50	50
Total Liabilities	2,319	3,116
Commitments and contingencies (Note 9)
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 shares issued and outstanding at June 30, 2023 and December 31, 2022	2,157	2,157
Additional paid-in capital	801,312	804,752
Treasury stock, at cost; 5,098 and 5,478 shares at June 30, 2023 and December 31, 2022, respectively	(44,437)	(48,410)
Accumulated deficit	(730,244)	(723,898)
Accumulated other comprehensive loss	(25)	(25)
Total Equity	28,763	34,576
Total Liabilities and Equity	$ 31,082	$ 37,692