CONDENSED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) - USD ($)	Total	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)
Balance, shares at Dec. 31, 2019		1,725,000
Balance, amount at Dec. 31, 2019	$ 11,083,000	$ 16,000	$ 16,039,000	$ (4,972,000)
Value of stock-based compensation, Shares		0
Value of stock-based compensation	49,000	$ 0	49,000	0
Issuance of common stock, net, shares		5,000
Issuance of common stock, net, amount	20,000	$ 0	20,000	0
Net loss	(925,000)	$ 0	0	(925,000)
Balance, shares at Mar. 31, 2020		1,730,000
Balance, amount at Mar. 31, 2020	10,227,000	$ 16,000	16,108,000	(5,897,000)
Balance, shares at Dec. 31, 2019		1,725,000
Balance, amount at Dec. 31, 2019	11,083,000	$ 16,000	16,039,000	(4,972,000)
Net loss	(3,654,000)
Balance, shares at Sep. 30, 2020		1,749,000
Balance, amount at Sep. 30, 2020	7,602,000	$ 17,000	16,211,000	(8,626,000)
Balance, shares at Mar. 31, 2020		1,730,000
Balance, amount at Mar. 31, 2020	10,227,000	$ 16,000	16,108,000	(5,897,000)
Value of stock-based compensation, Shares		0
Value of stock-based compensation	59,000	0	59,000	0
Net loss	(1,843,000)	$ 0	0	(1,843,000)
Repurchase of common stock upon vesting of restricted stock units, shares		4,000
Repurchase of common stock upon vesting of restricted stock units, amount	0	$ 0	0	0
Balance, shares at Jun. 30, 2020		1,734,000
Balance, amount at Jun. 30, 2020	8,443,000	$ 16,000	16,167,000	(7,740,000)
Value of stock-based compensation, Shares		0
Value of stock-based compensation	37,000	0	37,000	0
Issuance of common stock, net, amount	9,000	0	9,000	0
Net loss	(886,000)	$ 0	0	(886,000)
Vesting of restricted stock units offset by repurchase of common stock upon vesting of retricted stock units and awards, shares		13,000
Vesting of restricted stock units offset by repurchase of common stock upon vesting of retricted stock units and awards, amount	(1,000)	$ 1,000	(2,000)	0
Common stock issued for accrued liabilities, shares		2,000
Balance, shares at Sep. 30, 2020		1,749,000
Balance, amount at Sep. 30, 2020	7,602,000	$ 17,000	16,211,000	(8,626,000)
Balance, shares at Dec. 31, 2020		1,748,000
Balance, amount at Dec. 31, 2020	6,668,000	$ 17,000	16,238,000	(9,587,000)
Value of stock-based compensation, Shares		$ 0
Value of stock-based compensation	56,000		56,000	0
Issuance of common stock, net, shares		6,000
Issuance of common stock, net, amount	26,000	$ 1,000	25,000	0
Net loss	(737,000)	$ 0	0	(737,000)
Balance, shares at Mar. 31, 2021		1,754,000
Balance, amount at Mar. 31, 2021	6,013,000	$ 18,000	16,319,000	(10,324,000)
Balance, shares at Dec. 31, 2020		1,748,000
Balance, amount at Dec. 31, 2020	6,668,000	$ 17,000	16,238,000	(9,587,000)
Net loss	(2,552,000)
Balance, shares at Sep. 30, 2021		1,768,000
Balance, amount at Sep. 30, 2021	4,322,000	$ 18,000	16,443,000	(12,139,000)
Balance, shares at Mar. 31, 2021		1,754,000
Balance, amount at Mar. 31, 2021	6,013,000	$ 18,000	16,319,000	(10,324,000)
Value of stock-based compensation, Shares		0
Value of stock-based compensation	86,000	0	86,000	0
Net loss	(894,000)	$ 0	0	(894,000)
Repurchase of common stock upon vesting of restricted stock units, shares		11,000
Repurchase of common stock upon vesting of restricted stock units, amount	(9,000)	$ 0	(9,000)	0
Balance, shares at Jun. 30, 2021		1,765,000
Balance, amount at Jun. 30, 2021	5,196,000	$ 18,000	16,396,000	(11,218,000)
Value of stock-based compensation, Shares		0
Value of stock-based compensation	56,000	0	56,000	0
Net loss	(921,000)	$ 0	0	(921,000)
Repurchase of common stock upon vesting of restricted stock units, shares		3,000
Repurchase of common stock upon vesting of restricted stock units, amount	(9,000)	$ 0	(9,000)	0
Balance, shares at Sep. 30, 2021		1,768,000
Balance, amount at Sep. 30, 2021	$ 4,322,000	$ 18,000	$ 16,443,000	$ (12,139,000)