Identified Intangible Assets and Goodwill, Net Schedule of Goodwill (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Dec. 31, 2019
Goodwill [Line Items]
Goodwill	$ 42,285	$ 37,971	$ 37,971
Goodwill, acquisitions	1,356	1,379	4,174
Goodwill, translation and other adjustments	163	138
Goodwill	43,804	39,488	42,285
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	1,317
Finite-Lived Intangible Assets, Amortization Expense, Year Two	2,308
Finite-Lived Intangible Assets, Amortization Expense, Year Three	2,078
Finite-Lived Intangible Assets, Amortization Expense, Year Four	1,909
Finite-Lived Intangible Assets, Amortization Expense, Year Five	1,435
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	1,385
Intangible Assets, Net (Excluding Goodwill)	10,432		10,934
Utility [Member]
Goodwill [Line Items]
Goodwill	4,911	4,911	4,911
Goodwill, acquisitions	0	0
Goodwill, translation and other adjustments	0	0
Goodwill	4,911	4,911	4,911
Residential commercial [Member]
Goodwill [Line Items]
Goodwill	37,374	33,060	33,060
Goodwill, acquisitions	1,356	1,379
Goodwill, translation and other adjustments	163	138
Goodwill	$ 38,893	$ 34,577	$ 37,374