Goodwill and intangible assets - Schedule of indefinite life assets not subject to amortization (Details) - Tradenames $ in Thousands	6 Months Ended
Jun. 27, 2020 USD ($)
Indefinite-lived Intangible Assets [Roll Forward]
Balance as of December 31, 2019	$ 702,732
Currency translation during the period	(13,508)
Balance as of June 27, 2020	$ 689,224

Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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