Condensed Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from (used in) operating activities
Net income (loss)	$ (73)	$ 72
Adjustments to reconcile net income (loss) to net cash from (used in) operating activities:
Depreciation and amortization	181	154
Deferred income taxes	(18)	(13)
Stock-based compensation expense	4	5
Interest accrued on treasury bills	0	(84)
Loss on investments	3	0
Change in:
Trade receivables	(18)	(399)
Inventories	(40)	(94)
Other current assets	(4)	0
Accounts payable	15	125
Accrued expenses	201	150
Income tax receivable/payable	(11)	32
Net cash from (used in) operating activities	240	(52)
Cash flows from (used in) investing activities
Purchases of treasury bills	(6,748)	(6,916)
Proceeds from the maturity of treasury bills	0	7,000
Purchase of property and equipment	(12)	(61)
Net cash from (used in) investing activities	(6,760)	23
Cash flows used in financing activities
Payments on financing lease	(3)	(3)
Proceeds from loans	645	0
Repayment of loan principal	(645)	0
Net cash used in financing activities	(3)	(3)
Net decrease in cash and cash equivalents	(6,523)	(32)
Cash and cash equivalents, beginning	8,785	1,057
Cash and cash equivalents, ending	2,262	1,025
Supplemental cash flow information
Cash paid for income taxes	11	1
Cash paid for interest	$ 1	$ 1