Income Taxes - Components of Income, Provision For and Reconciliation of Tax (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Income before provision for income taxes:
U.S.									$ 20,778	$ 21,118	$ 12,248
Foreign									6,019	7,815	2,916
Income before provision for income taxes and noncontrolling interest	$ 6,059	$ 6,691	$ 7,947	$ 6,100	$ 8,331	$ 4,939	$ 9,737	$ 5,926	26,797	28,933	15,164
Currently payable:
Federal									4,252	4,015	4,515
Foreign									1,119	1,487	493
State									1,838	1,788	804
Currently payable									7,209	7,290	5,812
Deferred:
Federal									(869)	(384)	1,809
Foreign									331	(88)	(85)
State									(621)	(357)	(73)
Deferred									(1,159)	(829)	1,651
Provision (benefit) for income taxes									$ 6,050	$ 6,461	$ 7,463
Reconciliation of tax rates with the federal statutory rate
Federal statutory rate (as a percent)									21.00%	21.00%	35.00%
State income taxes, net of federal income tax benefit (as a percent)									5.50%	4.90%	3.90%
Tax law changes (as a percent)										0.90%	23.70%
Share-based compensation (as a percent)									(5.00%)	(6.30%)	(15.80%)
Meals & Entertainment Expense									1.70%	1.30%	3.00%
Executive Compensation									1.60%	1.00%	1.80%
Foreign rate differential (as a percent)										0.00%	2.80%
Uncertain tax positions (as a percent)									(2.50%)	(1.10%)	(0.10%)
Other (as a percent)									0.30%	0.60%	0.50%
Effective tax rate (as a percent)									22.60%	22.30%	49.20%