Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Capital in excess of par	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance at at Dec. 31, 2016	$ 643	$ 1,765	$ 65,169	$ 15,373
Balance at (in shares) at Dec. 31, 2016	2,574,264			903,097
Consolidated Statements of Shareholders' Equity
Net income			1,818		$ 1,818
Compensation of Board of Directors by issuance of treasury shares		122		$ (204)
Compensation of Board of Directors by issuance of treasury shares (in shares)				(12,000)
Purchase of treasury shares				$ 26
Purchase of treasury shares (in shares)				1,000	1,000
Balance at at Dec. 30, 2017	$ 643	1,887	66,987	$ 15,195	$ 54,322
Balance (in shares) at Dec. 30, 2017	2,574,264			892,097
Consolidated Statements of Shareholders' Equity
Net income			(5,856)		$ (5,856)
Compensation of Board of Directors by issuance of treasury shares		43		$ (272)
Compensation of Board of Directors by issuance of treasury shares (in shares)				(16,000)
Purchase of treasury shares				$ 5
Purchase of treasury shares (in shares)				312	0
Balance at at Dec. 29, 2018	$ 643	$ 1,930	$ 61,131	$ 14,928	$ 48,776
Balance (in shares) at Dec. 29, 2018	2,574,264			876,409