Acquisitions - Purchase Price allocation (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Business Acquisition [Line Items]
Current assets	$ 134,817
Property, plant and equipment, net	6,767
Other assets	346
Total assets acquired	220,467
Current liabilities	33,211
Long-term liabilities	2,871
Total liabilities assumed	36,082
Total purchase price	184,385
Trade name
Business Acquisition [Line Items]
Finite-lived Intangibles assets acquired	7,700
Customer relationships
Business Acquisition [Line Items]
Finite-lived Intangibles assets acquired	48,800
Non-compete agreements
Business Acquisition [Line Items]
Finite-lived Intangibles assets acquired	1,000
Developed technology
Business Acquisition [Line Items]
Finite-lived Intangibles assets acquired	1,400
Goodwill [Member]
Business Acquisition [Line Items]
Finite-lived Intangibles assets acquired	$ 19,637