Revenue - Summary of Revenues Disaggregated by Product Line (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation Of Revenue [Line Items]
Revenue	$ 2,125.9	$ 2,000.1	$ 6,499.6	$ 5,687.1
Packaging
Disaggregation Of Revenue [Line Items]
Revenue	1,940.2	1,829.4	5,971.6	5,171.4
Paper
Disaggregation Of Revenue [Line Items]
Revenue	165.3	150.3	468.6	457.1
Corporate and Other
Disaggregation Of Revenue [Line Items]
Revenue	$ 20.4	$ 20.4	$ 59.4	$ 58.6