Goodwill and Other Intangible Assets, Net Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 86,257	$ 56,753
Accumulated Amortization	12,441	7,325
Customer Lists and Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	79,517	50,798
Accumulated Amortization	9,017	5,135
Amortization period minimum, in years	8
Amortization period maximum, in years	21
Trademarks and Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	1,824	1,396
Accumulated Amortization	703	403
Amortization period minimum, in years	3
Amortization period maximum, in years	7
Non-Compete Agreements and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	4,280	3,902
Accumulated Amortization	2,254	1,345
Amortization period minimum, in years	1
Amortization period maximum, in years	9
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	636	657
Accumulated Amortization	$ 467	$ 442
Amortization period minimum, in years	17
Amortization period maximum, in years	17