CONDENSED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance at at Dec. 30, 2017	$ 643	$ 1,887	$ 66,987	$ (15,195)	$ 54,322
Balance at (in shares) at Dec. 30, 2017	2,574,264			892,097
Consolidated Statements of Shareholders' Equity
Net income (loss)			(6,193)		(6,193)
Compensation of Board of Directors by issuance of treasury shares		43		$ 271	314
Compensation of Board of Directors by issuance of treasury shares (in shares)				(16,000)
Purchase of treasury shares (in shares)				112
Balance at at Mar. 31, 2018	$ 643	1,930	60,794	$ (14,924)	48,443
Balance (in shares) at Mar. 31, 2018	2,574,264			876,209
Balance at at Dec. 29, 2018	$ 643	1,930	61,131	$ (14,928)	48,776
Balance at (in shares) at Dec. 29, 2018	2,574,264			876,409
Consolidated Statements of Shareholders' Equity
Net income (loss)			13,322		13,322
Compensation of Board of Directors by issuance of treasury shares		83		$ 358	441
Compensation of Board of Directors by issuance of treasury shares (in shares)				(21,000)
Purchase of treasury shares				$ (69)	(69)
Purchase of treasury shares (in shares)				3,368
Balance at at Mar. 30, 2019	$ 643	$ 2,013	$ 74,453	$ (14,639)	$ 62,470
Balance (in shares) at Mar. 30, 2019	2,574,264			858,777