The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2611-110228

Name:	us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Fair value measurement - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Debt Instrument
Impairment of fixed asstes	$ 3.7	$ 0.0	$ 3.7	$ 0.0
Secured credit facilities \| Secured debt \| LIBOR
Debt Instrument
Variable rate floor (percent)			1.00%
Euro Term Loan \| Term loan \| EURIBOR
Debt Instrument
Variable rate floor (percent)			0.00%