Other expense (income) (Summary of other expense (income)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Component Of Other Expense (Income) Nonoperating [Line Items]
Total other expense (income)	$ 6,387	$ (1,825)
Foreign Currency (Gains) Losses, Net [Member]
Component Of Other Expense (Income) Nonoperating [Line Items]
Total other expense (income)	3,799	(5,650)
All Other, Net [Member]
Component Of Other Expense (Income) Nonoperating [Line Items]
Total other expense (income)	$ 2,588	$ 3,825