Related party transactions - Transactions with Non-Gates entities (Details) - Non-Gates entities controlled by non-controlling shareholders - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018	Dec. 29, 2018
Related Party Transaction [Line Items]
Sales	$ 12.7	$ 13.7	$ 38.5	$ 45.4
Purchases	(5.0)	$ (5.5)	(15.3)	$ (16.0)
Receivables	4.4		4.4		$ 0.6
Payables	$ (5.4)		$ (5.4)		$ (0.3)

For an unclassified balance sheet, amounts due from related parties including affiliates, employees, joint ventures, officers and stockholders, immediate families thereof, and pension funds.

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Carrying amount as of the balance sheet date of obligations due all related parties.

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