Identified Intangible Assets and Goodwill, Net (Details) - USD ($) $ in Thousands	Mar. 28, 2020	Dec. 31, 2019	Mar. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets, gross	$ 44,356	$ 44,094
Accumulated amortization	33,261	33,160
Identified intangible assets, net	11,095	10,934
Goodwill	43,780	42,285	$ 39,328	$ 37,971
Customer lists/relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets, gross	28,478	28,301
Accumulated amortization	20,024	20,024
Employment-related [Member]
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets, gross	8,485	8,391
Accumulated amortization	7,448	7,348
Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets, gross	7,393	7,402
Accumulated amortization	$ 5,789	$ 5,788