Condensed Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from (used in) operating activities
Net loss	$ (91)	$ (31)
Adjustments to reconcile net loss to net cash from (used in) operating activities:
Depreciation and amortization	90	77
Deferred income taxes	(4)	3
Stock-based compensation expense	3	3
Interest accrued on treasury bills	0	(44)
Loss on investments	3	0
Change in:
Trade receivables	102	(179)
Inventories	(26)	(20)
Other current assets	(45)	(12)
Accounts payable	69	91
Accrued expenses	(20)	12
Income tax receivable/payable	(15)	(12)
Net cash from (used in) operating activities	66	(112)
Cash flows from (used in) investing activities
Purchases of treasury bills	(999)	(3,945)
Proceeds from the maturity of treasury bills	0	4,000
Purchase of property and equipment	0	(45)
Net cash from (used in) investing activities	(999)	10
Cash flows used in financing activities
Payments on financing lease	(2)	(1)
Net cash used in financing activities	(2)	(1)
Net decrease in cash and cash equivalents	(935)	(103)
Cash and cash equivalents, beginning	8,785	1,057
Cash and cash equivalents, ending	7,850	954
Supplemental cash flow information
Cash paid for income taxes	$ 0	$ 0