Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
CURRENT ASSETS
Cash and cash equivalents	$ 5,377	$ 5,700
Accounts receivable, net	1,253	1,166
Investment in debt securities, current portion	2,589	2,671
Prepaid expenses and other assets	347	467
Total current assets	9,566	10,004
PROPERTY & EQUIPMENT, NET	16,027	16,059
OTHER ASSETS
Investment in debt securities, net of current portion	587	464
Investment in joint venture	1,627	1,608
Deferred development costs	12,860	12,815
Other noncurrent assets	1,388	1,273
Total other assets	16,462	16,160
TOTAL ASSETS	42,055	42,223
CURRENT LIABILITIES
Accounts payable	1,408	1,154
Payroll and employee benefits	217	502
Accrued retirement benefits, current portion	142	142
Deferred revenue, current portion	308	217
Other current liabilities	475	465
Total current liabilities	2,550	2,480
LONG-TERM LIABILITIES
Accrued retirement benefits, net of current portion	1,528	1,550
Other noncurrent liabilities	12	14
Total long-term liabilities	4,951	5,039
TOTAL LIABILITIES	7,501	7,519
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY
Preferred stock--$0.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock--$0.0001 par value; 43,000,000 shares authorized; 19,641,045 and 19,615,350 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	85,201	84,680
Additional paid-in-capital	11,174	10,538
Accumulated deficit	(54,992)	(53,617)
Accumulated other comprehensive loss	(6,829)	(6,897)
Total stockholders' equity	34,554	34,704
TOTAL LIABILITIES & STOCKHOLDERS' EQUITY	42,055	42,223
Excluding Deposits [Member]
LONG-TERM LIABILITIES
Deferred revenue, net of current portion	1,333	1,367
Member Deposits [Member]
LONG-TERM LIABILITIES
Deferred revenue, net of current portion	$ 2,078	$ 2,108