Derivative financial instruments - Fair Values of Derivative Instruments (Details) - USD ($) $ in Millions	Jun. 27, 2020	Dec. 28, 2019
Derivatives, Fair Value
Net	$ (80.7)	$ (55.5)
Prepaid expenses and other assets
Derivatives, Fair Value
Derivative assets	1.6	5.4
Other non- current assets
Derivatives, Fair Value
Derivative assets	0.0	0.0
Accrued expenses and other current liabilities
Derivatives, Fair Value
Derivative liabilities	(13.9)	(9.6)
Other non- current liabilities
Derivatives, Fair Value
Derivative liabilities	(68.4)	(51.3)
Derivatives designated as hedging instruments: \| —Currency swaps
Derivatives, Fair Value
Net	(16.1)	(15.1)
Derivatives designated as hedging instruments: \| —Currency swaps \| Prepaid expenses and other assets
Derivatives, Fair Value
Derivative assets	1.3	4.2
Derivatives designated as hedging instruments: \| —Currency swaps \| Other non- current liabilities
Derivatives, Fair Value
Derivative liabilities	(17.4)	(19.3)
Derivatives designated as hedging instruments: \| —Interest rate caps
Derivatives, Fair Value
Net	(3.4)	(7.0)
Derivatives designated as hedging instruments: \| —Interest rate caps \| Accrued expenses and other current liabilities
Derivatives, Fair Value
Derivative liabilities	(1.0)	(4.0)
Derivatives designated as hedging instruments: \| —Interest rate caps \| Other non- current liabilities
Derivatives, Fair Value
Derivative liabilities	(2.4)	(3.0)
Derivatives designated as hedging instruments: \| —Interest rate swaps
Derivatives, Fair Value
Net	(60.7)	(34.3)
Derivatives designated as hedging instruments: \| —Interest rate swaps \| Accrued expenses and other current liabilities
Derivatives, Fair Value
Derivative liabilities	(12.1)	(5.3)
Derivatives designated as hedging instruments: \| —Interest rate swaps \| Other non- current liabilities
Derivatives, Fair Value
Derivative liabilities	(48.6)	(29.0)
Derivatives not designated as hedging instruments: \| —Currency swaps
Derivatives, Fair Value
Net	0.1	(0.1)
Derivatives not designated as hedging instruments: \| —Currency swaps \| Prepaid expenses and other assets
Derivatives, Fair Value
Derivative assets	0.1
Derivatives not designated as hedging instruments: \| —Currency swaps \| Accrued expenses and other current liabilities
Derivatives, Fair Value
Derivative liabilities	0.0	(0.1)
Derivatives not designated as hedging instruments: \| —Currency forward contracts
Derivatives, Fair Value
Net	(0.6)	1.0
Derivatives not designated as hedging instruments: \| —Currency forward contracts \| Prepaid expenses and other assets
Derivatives, Fair Value
Derivative assets	0.2	1.2
Derivatives not designated as hedging instruments: \| —Currency forward contracts \| Accrued expenses and other current liabilities
Derivatives, Fair Value
Derivative liabilities	$ (0.8)	$ (0.2)

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
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- Definition

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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