Cost in Excess of Net Assets of Companies Acquired - Intangibles (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended			6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended		6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011	Dec. 31, 2011	Jun. 30, 2012 Customer Relationships [Member] Years	Dec. 31, 2011 Customer Relationships [Member] Years	Jun. 30, 2012 Patented Technology [Member] Years	Dec. 31, 2011 Patented Technology [Member] Years	Dec. 31, 2011 Procurement Agreement [Member] Years	Jun. 30, 2012 Other Intangible Assets [Member] Years		Dec. 31, 2011 Other Intangible Assets [Member]		Jun. 30, 2012 Trade Names [Member]	Dec. 31, 2011 Trade Names [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life						11	11	5	6	5
Gross Carrying Amount	$ 498,679		$ 498,679		$ 484,331	$ 298,442	$ 267,729	$ 11,791	$ 11,029	$ 12,000	$ 9,446	[1]	$ 14,573	[1]	$ 179,000	$ 179,000
Accumulated Amortization	(92,355)		(92,355)		(91,568)	(83,677)	(69,762)	(1,490)	(693)	(11,400)	(7,188)	[1]	(9,713)	[1]	0	0
Net	406,324		406,324		392,763	214,765	197,967	10,301	10,336	600	2,258	[1]	4,860	[1]	179,000	179,000
Finite-Lived Intangible Assets, Useful Life, Minimum											1
Finite-Lived Intangible Assets, Useful Life, Maximum											3
Amortization of Intangible Assets	$ 8,959	$ 9,280	$ 18,630	$ 16,163

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