Acquisitions and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Y	Apr. 02, 2011	Dec. 31, 2011
Acquisitions and Dispositions (Textual) [Abstract]
Maximum potential earn-out, payment period		4 years
Acquisitions and Dispositions (Additional Textual) [Abstract]
Gross carrying amounts of finite-lived identifiable intangible assets	$ 184,490		$ 183,557
Maximum amortization period for finite-lived identifiable intangible assets	16
Net carrying amounts of finite-lived identifiable intangible assets	71,107		73,330
Amortization expense	2,925	3,205
Business acquisition potential earn out paid	333
Arete Sistemas [Member]
Acquisitions and Dispositions (Textual) [Abstract]
Estimated useful lives of Identifiable intangible assets		10
Initial cash payment for entity acquired		1,066
Hold-back amount to be released upon settlement of certain closing matters		1,040
Maximum potential earn-out, amount		5,000
Estimated fair value of payout		2,062
Identifiable intangible assets		4,142
Aggregate purchase price		$ 4,168