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, 2018	$ 24,082	$ 1,241	$ 7,063	$ 15,778
Beginning Balance, Shares at Dec. 31, 2018	12,408	12,408
Stock-based compensation, Value	$ 42		42
Net income (loss)	(330)			(330)
Ending Balance, Value at Mar. 31, 2019	23,794	$ 1,241	7,105	15,448
Ending Balance, Shares at Mar. 31, 2019		12,408
Beginning Balance, Value at Dec. 31, 2018	$ 24,082	$ 1,241	7,063	15,778
Beginning Balance, Shares at Dec. 31, 2018	12,408	12,408
Net income (loss)	$ (659)
Ending Balance, Value at Sep. 30, 2019	23,585	$ 1,246	7,220	15,119
Ending Balance, Shares at Sep. 30, 2019		12,462
Beginning Balance, Value at Mar. 31, 2019	23,794	$ 1,241	7,105	15,448
Beginning Balance, Shares at Mar. 31, 2019		12,408
Stock-based compensation, Value	42		42
Stock options exercised	41	$ 5	36
Stock options exercised, Shares		51
Net income (loss)	(716)			(716)
Ending Balance, Value at Jun. 30, 2019	$ 23,161	$ 1,246	7,183	14,732
Ending Balance, Shares at Jun. 30, 2019	12,460	12,459
Stock-based compensation, Value	$ 35		35
Stock options exercised	2		2
Stock options exercised, Shares		3
Net income (loss)	387			387
Ending Balance, Value at Sep. 30, 2019	23,585	$ 1,246	7,220	15,119
Ending Balance, Shares at Sep. 30, 2019		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
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	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	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	12,513