Fair value measurement - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Dec. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative liabilities	$ (103.0)	$ (79.4)
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets	54.1	77.5
Derivative liabilities	(103.0)	(79.4)
Cash equivalents	129.0	0.0
Quoted prices in active markets (Level 1) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets	0.0	0.0
Derivative liabilities	0.0	0.0
Cash equivalents	76.2	0.0
Significant observable inputs (Level 2) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative assets	54.1	77.5
Derivative liabilities	(103.0)	(79.4)
Cash equivalents	$ 52.8	$ 0.0