Restructuring and impairment charges - Expected costs to be incurred (Details) - Respiratory divestiture plan - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2023	Jun. 26, 2022	Jul. 02, 2023	Jun. 26, 2022
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 2.0	$ 2.4	$ 4.1	$ 4.4
Aggregate restructuring charges			3.5
Restructuring costs			16.3
Restructuring reserve	3.5		3.5
Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	24.0		24.0
Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	30.0		30.0
Special Termination Benefit And Other Restructuring | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	5.0		5.0
Special Termination Benefit And Other Restructuring | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	8.0		8.0
Accelerated Depreciation And Other Costs | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	19.0		19.0
Accelerated Depreciation And Other Costs | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	$ 22.0		$ 22.0