Commitments and Contingencies (Details) ft² in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 02, 2021 USD ($)	Sep. 26, 2020 USD ($)	Oct. 02, 2021 USD ($)	Sep. 26, 2020 USD ($)	Dec. 31, 2020 USD ($)	Jun. 29, 2020 ft² building
Loss Contingencies [Line Items]
Revenue	$ 163,227	$ 150,371	$ 480,570	$ 471,155
Related cost of sales	127,912	116,906	375,373	368,218
Structural Systems
Loss Contingencies [Line Items]
Revenue	58,506	$ 46,901	173,948	$ 177,615
El Mirage and Monrovia, California | Structural Systems
Loss Contingencies [Line Items]
Reserve for estimated liability	1,500		1,500		$ 1,500
West Covina, California | Structural Systems
Loss Contingencies [Line Items]
Reserve for estimated liability	400		400		400
West Covina, California | Minimum | Structural Systems
Loss Contingencies [Line Items]
Possible loss	400		400
West Covina, California | Maximum | Structural Systems
Loss Contingencies [Line Items]
Possible loss	$ 3,100		3,100
Facility Fire In Guaymas, Mexico | Damage from Facility Fire
Loss Contingencies [Line Items]
Number of buildings | building						2
Real estate property (in sqft) | ft²						62
Loss contingency, receivable, proceeds			$ 13,500
Facility Fire In Guaymas, Mexico | Damage from Facility Fire | Property, Plant and Equipment
Loss Contingencies [Line Items]
Carrying value of impaired assets					7,100
Facility Fire In Guaymas, Mexico | Damage from Facility Fire | Inventories
Loss Contingencies [Line Items]
Carrying value of impaired assets					3,400
Facility Fire In Guaymas, Mexico | Damage from Facility Fire | Revision of Prior Period, Reclassification, Adjustment
Loss Contingencies [Line Items]
Revenue					800
Related cost of sales					$ 500