Cost in Excess of Net Assets of Companies Acquired and Intangible Assets, net Cost in Excess of Net Assets of Companies Acquired and Intangible Assets, net - Intangible Assets (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended										12 Months Ended
	Dec. 31, 2014		Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013		Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 513,561					$ 567,478					$ 513,561		$ 567,478
Accumulated amortization	(177,850)					(141,409)					(177,850)		(141,409)
Intangible assets, net	335,711					426,069					335,711		426,069
Impairment of Intangible Assets (Excluding Goodwill)											78,000
Impairment of intangible assets (excluding Goodwill), Net of Tax	47,911										47,911
Impairment of Intangible Assets (Excluding Goodwill), Net of Tax Per Share Basic											$ 0.49
Impairment of Intangible Assets (Excluding Goodwill), Net of Tax Per Share Diluted											$ 0.48
Amortization of Intangible Assets											44,063		36,769		36,508
Amortization of Intangible Assets Net of Tax	9,105		9,086	8,867	8,907	8,120		7,074	7,029	7,116	35,965		29,339		29,336
Amortization of Intangible Assets Net of Tax Per Share Basic											$ 0.36		$ 0.29		$ 0.27
Amortization of Intangible Assets Net of Tax Per Share Diluted											$ 0.36		$ 0.28		$ 0.26
Future Amortization Expense, Year One	43,501										43,501
Future Amortization Expense, Year Two	41,627										41,627
Future Amortization Expense, Year Three	38,509										38,509
Future Amortization Expense, Year Four	32,892										32,892
Future Amortization Expense, Year Five	26,462										26,462
Customer Relationships [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted Average Useful Life											10 years		10 years
Gross carrying amount	402,036					374,244					402,036		374,244
Accumulated amortization	(171,071)					(134,817)					(171,071)		(134,817)
Intangible assets, net	230,965					239,427					230,965		239,427
Patented Technology [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted Average Useful Life											5 years		5 years
Gross carrying amount	8,806					9,625					8,806		9,625
Accumulated amortization	(5,444)					(4,051)					(5,444)		(4,051)
Intangible assets, net	3,362					5,574					3,362		5,574
Other Intangible Assets [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying amount	1,719	[1]				4,609	[2]				1,719	[1]	4,609	[2]
Accumulated amortization	(1,335)	[1]				(2,541)	[2]				(1,335)	[1]	(2,541)	[2]
Intangible assets, net	384	[1]				2,068	[2]				384	[1]	2,068	[2]
Acquired Finite-lived Intangible Asset, Useful Life, Minimum											2		1
Acquired Finite-lived Intangible Asset, Useful Life, Maximum											3		3
Trade Names [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying amount	101,000					179,000					101,000		179,000
Accumulated amortization	0					0					0		0
Intangible assets, net	$ 101,000					$ 179,000					$ 101,000		$ 179,000

[1] Consists of non-competition agreements with useful lives ranging from two to three years.

[2] Consists of non-competition agreements and sales backlog with useful lives ranging from one to three years.