Revenue - Summary of changes to rebate reserves (Details) - USD ($) $ in Millions		12 Months Ended
		Jan. 02, 2022	Jan. 03, 2021	Dec. 29, 2019
Revenue From Contract With Customer [Abstract]
Balance at beginning of fiscal year		$ 42.4	$ 32.1	$ 30.6
Additions		267.6	222.4	207.0
Deductions(a)	[1]	(251.1)	(212.1)	(205.5)
Balance at end of fiscal year		$ 58.9	$ 42.4	$ 32.1

[1] Primarily reflects payments of customer rebates.