Segment financial information - product lines (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation by product line
Net sales	$ 7,512.4	$ 7,386.1	$ 6,393.6
Proprietary materials & consumables
Disaggregation by product line
Net sales	2,898.4	2,548.2	2,043.6
Third party materials & consumables
Disaggregation by product line
Net sales	2,704.1	2,906.3	2,671.8
Services & specialty procurement
Disaggregation by product line
Net sales	921.0	922.6	817.5
Equipment & instrumentation
Disaggregation by product line
Net sales	$ 988.9	$ 1,009.0	$ 860.7