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, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Finite And Indefinite Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 35,359		$ 21,132		$ 15,349
Finite And Indefinite Lived Intangible Assets Gross	484,331		369,093
Finite-Lived Intangible Assets, Accumulated Amortization	(91,568)		(58,246)
Intangible assets, net	392,763		310,847
Future Amortization Expense, Year One	32,315
Future Amortization Expense, Year Two	28,802
Future Amortization Expense, Year Three	28,271
Future Amortization Expense, Year Four	27,896
Future Amortization Expense, Year Five	26,265
Trade Names [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Finite And Indefinite Lived Intangible Assets Gross	179,000		130,000
Finite-Lived Intangible Assets, Accumulated Amortization	0		0
Intangible assets, net	179,000		130,000
Customer Relationships [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life	11		12
Finite And Indefinite Lived Intangible Assets Gross	267,729		217,294
Finite-Lived Intangible Assets, Accumulated Amortization	(69,762)		(47,336)
Intangible assets, net	197,967		169,958
Patented Technology [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life	6		10
Finite And Indefinite Lived Intangible Assets Gross	11,029		1,700
Finite-Lived Intangible Assets, Accumulated Amortization	(693)		(57)
Intangible assets, net	10,336		1,643
Procurement Agreement [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life	5		5
Finite And Indefinite Lived Intangible Assets Gross	12,000		12,000
Finite-Lived Intangible Assets, Accumulated Amortization	(11,400)		(9,000)
Intangible assets, net	600		3,000
Other Intangible Assets [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Useful Life, Minimum	1
Acquired Finite-lived Intangible Asset, Useful Life, Maximum	3
Finite And Indefinite Lived Intangible Assets Gross	14,573	[1]	8,099	[1]
Finite-Lived Intangible Assets, Accumulated Amortization	(9,713)	[1]	(1,853)	[1]
Intangible assets, net	$ 4,860	[1]	$ 6,246	[1]

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