Summary of Significant Accounting Policies - Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross Carrying amount	$ 103,390	$ 95,743
Accumulated Amortization	(59,037)	(41,846)
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Weighted Avg Remaining LIfe	3 years 3 months 18 days	3 years 1 month 6 days
Gross Carrying amount	76,763	67,904
Accumulated Amortization	(40,349)	(28,435)
Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Weighted Avg Remaining LIfe	1 year	2 years
Gross Carrying amount	8,751	9,733
Accumulated Amortization	(6,713)	(4,378)
Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Weighted Avg Remaining LIfe	3 years 3 months 18 days	1 year 8 months 12 days
Gross Carrying amount	17,876	18,106
Accumulated Amortization	(11,975)	(9,033)
Tradenames And Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 188,988	$ 180,829