Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance (in shares) at Dec. 30, 2017	15,017,522				2,823,172
Balance at Dec. 30, 2017	$ 751	$ 104,540	$ (2,395)	$ (65,878)	$ (14,987)	$ 22,031
Issuance of stock under employee stock purchase plan (in shares)	45,408
Issuance of stock under employee stock purchase plan	$ 2	192				194
Translation adjustment			(70)			(70)
Share-based compensation expense		112				112
Net income				1,051		1,051
Issuance of stock under employee stock purchase plan (in shares)	45,408
Balance (in shares) at Mar. 31, 2018	15,062,930				2,823,172
Balance at Mar. 31, 2018	$ 753	104,844	(2,465)	(64,827)	$ (14,987)	23,318
Balance (in shares) at Dec. 30, 2017	15,017,522				2,823,172
Balance at Dec. 30, 2017	$ 751	104,540	(2,395)	(65,878)	$ (14,987)	22,031
Translation adjustment						(141)
Net income						1,432
Balance (in shares) at Jun. 30, 2018	15,062,930				2,823,172
Balance at Jun. 30, 2018	$ 753	104,933	(2,536)	(64,446)	$ (14,987)	23,717
Balance (in shares) at Mar. 31, 2018	15,062,930				2,823,172
Balance at Mar. 31, 2018	$ 753	104,844	(2,465)	(64,827)	$ (14,987)	23,318
Issuance of stock under employee stock purchase plan (in shares)
Issuance of stock under employee stock purchase plan
Translation adjustment			(71)			(71)
Share-based compensation expense		89				89
Net income				381		381
Issuance of stock under employee stock purchase plan (in shares)
Balance (in shares) at Jun. 30, 2018	15,062,930				2,823,172
Balance at Jun. 30, 2018	$ 753	104,933	(2,536)	(64,446)	$ (14,987)	23,717
Balance (in shares) at Dec. 29, 2018	15,578,345				2,823,172
Balance at Dec. 29, 2018	$ 778	107,326	(2,755)	(63,163)	$ (14,987)	27,199
Issuance of stock under employee stock purchase plan (in shares)	59,451
Issuance of stock under employee stock purchase plan	$ 3	162				165
Translation adjustment			11			11
Share-based compensation expense		241				241
Issuance of stock upon vesting of restricted stock units (in shares)	57,148
Issuance of stock upon vesting of restricted stock units	$ 3	(3)
Net income				1,463		1,463
Issuance of stock under employee stock purchase plan (in shares)	59,451
Balance (in shares) at Mar. 30, 2019	15,694,944				2,823,172
Balance at Mar. 30, 2019	$ 784	107,726	(2,744)	(61,700)	$ (14,987)	29,079
Balance (in shares) at Dec. 29, 2018	15,578,345				2,823,172
Balance at Dec. 29, 2018	$ 778	107,326	(2,755)	(63,163)	$ (14,987)	27,199
Translation adjustment						23
Net income						2,714
Balance (in shares) at Jun. 29, 2019	15,719,944				2,823,172
Balance at Jun. 29, 2019	$ 785	107,932	(2,732)	(60,449)	$ (14,987)	30,549
Balance (in shares) at Mar. 30, 2019	15,694,944				2,823,172
Balance at Mar. 30, 2019	$ 784	107,726	(2,744)	(61,700)	$ (14,987)	29,079
Issuance of stock under employee stock purchase plan (in shares)
Issuance of stock under employee stock purchase plan
Translation adjustment			12			12
Share-based compensation expense		207				207
Issuance of stock upon vesting of restricted stock units (in shares)	25,000
Issuance of stock upon vesting of restricted stock units	$ 1	(1)
Net income				1,251		1,251
Issuance of stock under employee stock purchase plan (in shares)
Balance (in shares) at Jun. 29, 2019	15,719,944				2,823,172
Balance at Jun. 29, 2019	$ 785	$ 107,932	$ (2,732)	$ (60,449)	$ (14,987)	$ 30,549