Identified Intangible Assets and Goodwill, Net (Details) - USD ($) $ in Thousands	Jul. 01, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets, gross	$ 35,060	$ 30,488
Accumulated amortization	27,536	26,417
Identified intangible assets, net	7,524	4,071
Identified intangible assets and goodwill, net	41,355	34,376
Customer lists/relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets, gross	21,711	17,822
Accumulated amortization	16,036	15,171
Employment-related [Member]
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets, gross	7,389	7,032
Accumulated amortization	6,499	6,386
Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets, gross	5,960	5,634
Accumulated amortization	$ 5,001	$ 4,860