Fair Value Measurements (Narrative) (Details) (USD $)	6 Months Ended
	Jun. 29, 2014	Mar. 30, 2014	Dec. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 30, 2012	Jun. 29, 2014 Line of Credit, Maturing January 8, 2019 [Member]	Dec. 29, 2013 Line of Credit, Maturing December 16, 2016 [Member]	Jun. 29, 2014 2021 Notes [Member]	Dec. 29, 2013 2021 Notes [Member]	Oct. 25, 2011 2021 Notes [Member]	Jun. 29, 2014 Financing Lease Obligations [Member]	Dec. 29, 2013 Financing Lease Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							$ 700,000,000	$ 700,000,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	28,600,000
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	3,430,000	4,981,000	4,926,000	3,715,000	2,727,000	3,017,000
Business Combination, Contingent Consideration Arrangements, Description	Contingent consideration is measured at fair value at the acquisition date, based on the probability that revenue thresholds or product development milestones will be achieved during the earnout period, with changes in the fair value after the acquisition date affecting earnings to the extent it is to be settled in cash.
Business Combination, Contingent Consideration Arrangements, Maximum Period	3 years
Unsecured senior notes, face value									500,000,000		500,000,000
Revolving credit facility outstanding balance							358,000,000	397,000,000
Long-term Debt, Gross									497,500,000	497,400,000
Debt Instrument, Unamortized Discount									2,500,000	2,600,000	3,100,000
Unsecured senior notes, fair value									$ 533,200,000	$ 513,000,000		$ 39,800,000	$ 40,300,000
Business Combination, Contingent Consideration Arrangements, Weighted Average Period	1 year