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
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						(177)
Net income						2,116
Balance (in shares) at Sep. 29, 2018	15,108,399				2,823,172
Balance at Sep. 29, 2018	$ 755	105,243	(2,572)	(63,762)	$ (14,987)	24,677
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
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
Issuance of stock under employee stock purchase plan (in shares)	45,469
Issuance of stock under employee stock purchase plan	$ 2	189				191
Translation adjustment			(36)			(36)
Share-based compensation expense		121				121
Net income				684		684
Balance (in shares) at Sep. 29, 2018	15,108,399				2,823,172
Balance at Sep. 29, 2018	$ 755	105,243	(2,572)	(63,762)	$ (14,987)	24,677
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
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						(2)
Net income						3,049
Balance (in shares) at Sep. 28, 2019	15,779,019				2,823,172
Balance at Sep. 28, 2019	$ 788	108,121	(2,757)	(60,114)	$ (14,987)	31,051
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
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
Issuance of stock under employee stock purchase plan (in shares)	59,075
Issuance of stock under employee stock purchase plan	$ 3	153				156
Translation adjustment			(25)			(25)
Share-based compensation expense		24				24
Net income				335		335
Dividends forfeited		12				12
Balance (in shares) at Sep. 28, 2019	15,779,019				2,823,172
Balance at Sep. 28, 2019	$ 788	$ 108,121	$ (2,757)	$ (60,114)	$ (14,987)	$ 31,051