Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Capital in Excess of Par	Retained Earnings
Beginning Balance, Value at Dec. 31, 2019	$ 23,617	$ 1,246	$ 7,250	$ 15,121
Beginning Balance, Shares at Dec. 31, 2019	12,462	12,462
Stock-based compensation, Value	$ 36		36
Net income (loss)	277			277
Ending Balance, Value at Mar. 31, 2020	23,930	$ 1,246	7,286	15,398
Ending Balance, Shares at Mar. 31, 2020		12,462
Beginning Balance, Value at Dec. 31, 2019	$ 23,617	$ 1,246	7,250	15,121
Beginning Balance, Shares at Dec. 31, 2019	12,462	12,462
Net income (loss)	$ (318)
Ending Balance, Value at Sep. 30, 2020	23,472	$ 1,251	7,418	14,803
Ending Balance, Shares at Sep. 30, 2020		12,513
Beginning Balance, Value at Mar. 31, 2020	23,930	$ 1,246	7,286	15,398
Beginning Balance, Shares at Mar. 31, 2020		12,462
Stock-based compensation, Value	35		35
Net income (loss)	(78)			(78)
Ending Balance, Value at Jun. 30, 2020	$ 23,887	$ 1,246	7,321	15,320
Ending Balance, Shares at Jun. 30, 2020	12,462	12,462
Stock-based compensation, Value	$ 35		35
Stock options exercised, Value	67	$ 5	62
Stock options exercised, Shares		51
Net income (loss)	(517)			(517)
Ending Balance, Value at Sep. 30, 2020	23,472	$ 1,251	7,418	14,803
Ending Balance, Shares at Sep. 30, 2020		12,513
Beginning Balance, Value at Dec. 31, 2020	$ 22,465	$ 1,262	7,633	13,570
Beginning Balance, Shares at Dec. 31, 2020	12,618	12,618
Stock-based compensation, Value	$ 69		69
Net income (loss)	(280)			(280)
Ending Balance, Value at Mar. 31, 2021	22,254	$ 1,262	7,702	13,290
Ending Balance, Shares at Mar. 31, 2021		12,618
Beginning Balance, Value at Dec. 31, 2020	$ 22,465	$ 1,262	7,633	13,570
Beginning Balance, Shares at Dec. 31, 2020	12,618	12,618
Net income (loss)	$ (3,814)
Ending Balance, Value at Sep. 30, 2021	$ 18,807	$ 1,266	7,785	9,756
Ending Balance, Shares at Sep. 30, 2021	12,666	12,666
Beginning Balance, Value at Mar. 31, 2021	$ 22,254	$ 1,262	7,702	13,290
Beginning Balance, Shares at Mar. 31, 2021		12,618
Stock-based compensation, Value	33		33
Net income (loss)	(1,066)			(1,066)
Ending Balance, Value at Jun. 30, 2021	$ 21,221	$ 1,262	7,735	12,224
Ending Balance, Shares at Jun. 30, 2021	12,618	12,618
Stock-based compensation, Value	$ (3)		(3)
Stock options exercised, Value	57	$ 4	53
Stock options exercised, Shares		45
Restricted stock unit vesting, Shares		3
Net income (loss)	(2,468)			(2,468)
Ending Balance, Value at Sep. 30, 2021	$ 18,807	$ 1,266	$ 7,785	$ 9,756
Ending Balance, Shares at Sep. 30, 2021	12,666	12,666