Goodwill - Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016	Dec. 31, 2016
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 581,654		$ 581,654		$ 593,037
Accumulated Amortization	(264,219)		(264,219)		(256,155)
Net	317,435		317,435		$ 336,882
Amortization of Intangible Assets	12,364	$ 14,446	$ 25,264	$ 27,359
Customer Relationships [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted-Average Life			10 years		10 years
Gross Carrying Amount	471,906		$ 471,906		$ 476,176
Accumulated Amortization	(260,730)		(260,730)		(247,206)
Net	211,176		$ 211,176		$ 228,970
Developed Technology [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted-Average Life			5 years		5 years
Gross Carrying Amount	6,340		$ 6,340		$ 9,140
Accumulated Amortization	(2,409)		(2,409)		(4,435)
Net	3,931		$ 3,931		4,705
Other Intangible Assets [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted-Average Life			5 years
Gross Carrying Amount	2,408		$ 2,408		6,721	[1]
Accumulated Amortization	(1,080)		(1,080)		(4,514)	[1]
Net	1,328		1,328		2,207	[1]
Trade Names [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	101,000		101,000		101,000
Accumulated Amortization	0		0		0
Net	$ 101,000		$ 101,000		$ 101,000
Minimum [Member] | Other Intangible Assets [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Useful Life					2 years
Maximum [Member] | Other Intangible Assets [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Useful Life					5 years

[1] Consists of non-competition agreements, sales backlog, and an amortizable trade name with useful lives ranging from two to five years.