Goodwill and intangible assets (Schedule of indefinite life assets not subject to amortization) (Details) (Tradenames [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 30, 2013
Tradenames [Member]
Indefinite-lived Intangible Assets [Roll Forward]
Indefinite life assets not subject to amortization, beginning balance	$ 455,503
Intangible assets recognized during the period	16,835
Currency translation during the year	(8,067)
Indefinite life assets not subject to amortization, ending balance	$ 464,271

Carrying amount of assets (excluding financial assets) that lack physical substance, excluding goodwill, having a projected indefinite period of benefit.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16323-109275

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant