Acquisitions - Intangible Assets Acquired (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Years		Dec. 31, 2010 Years
RFPD and NuHorizons Combined [Member]
Intangible Assets Acquired As Part Of Business Combination [Line Items]
Business Acquisition, Purchase Price Allocation, Current Assets, Receivables	$ 194,312
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	90,900
Business Acquisition, Purchase Price Allocation, Current Assets, Inventory	169,881
Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment	11,278
Business Acquisition, Purchase Price Allocation, Other Noncurrent Assets	6,965
Business Acquisition, Purchase Price Allocation, Goodwill Amount	31,951
Business Acquisition, Purchase Price Allocation, Current Liabilities, Accounts Payable	(98,967)
Business Acquisition, Purchase Price Allocation, Current Liabilities, Accrued Liabilities	(18,900)
Business Acquisition, Purchase Price Allocation, Other Noncurrent Liabilities	(4,080)
Business Acquisition, Cost of Acquired Entity, Purchase Price	379,013
Intechra Shared and Converge Combined [Member]
Intangible Assets Acquired As Part Of Business Combination [Line Items]
Business Acquisition, Purchase Price Allocation, Current Assets, Receivables			91,001
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets			146,200
Business Acquisition, Purchase Price Allocation, Current Assets, Inventory			11,785
Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment			11,187
Business Acquisition, Purchase Price Allocation, Other Noncurrent Assets			8,615
Business Acquisition, Purchase Price Allocation, Goodwill Amount			342,446
Business Acquisition, Purchase Price Allocation, Current Liabilities, Accounts Payable			(38,961)
Business Acquisition, Purchase Price Allocation, Current Liabilities, Accrued Liabilities			(46,328)
Business Acquisition, Purchase Price Allocation, Other Noncurrent Liabilities			(38,552)
Business Acquisition, Cost of Acquired Entity, Purchase Price			487,393
Customer Relationships [Member] | RFPD and NuHorizons Combined [Member]
Intangible Assets Acquired As Part Of Business Combination [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	35,400
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life	8
Customer Relationships [Member] | Intechra Shared and Converge Combined [Member]
Intangible Assets Acquired As Part Of Business Combination [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets			59,800
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life	10
Trade Names [Member] | RFPD and NuHorizons Combined [Member]
Intangible Assets Acquired As Part Of Business Combination [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	49,000
Trade Names [Member] | Intechra Shared and Converge Combined [Member]
Intangible Assets Acquired As Part Of Business Combination [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets			78,000
Developed Technology [Member] | Intechra Shared and Converge Combined [Member]
Intangible Assets Acquired As Part Of Business Combination [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets			1,700
Other Intangibles [Member] | RFPD and NuHorizons Combined [Member]
Intangible Assets Acquired As Part Of Business Combination [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	6,500	[1]
Acquired Finite-lived Intangible Asset, Useful Life, Minimum	1
Acquired Finite-lived Intangible Asset, Useful Life, Maximum	3
Other Intangibles [Member] | Intechra Shared and Converge Combined [Member]
Intangible Assets Acquired As Part Of Business Combination [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets			$ 6,700	[2]
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life	10
Acquired Finite-lived Intangible Asset, Useful Life, Minimum			1
Acquired Finite-lived Intangible Asset, Useful Life, Maximum			2

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

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