Revenue - Summary of Revenues Disaggregated by Product Line (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Revenue	$ 7,730.3	$ 6,658.2	$ 6,964.3
Packaging
Disaggregation Of Revenue [Line Items]
Revenue	7,052.6	5,919.5	5,932.2
Paper
Disaggregation Of Revenue [Line Items]
Revenue	599.7	674.8	964.3
Corporate and Other
Disaggregation Of Revenue [Line Items]
Revenue	$ 78.0	$ 63.9	$ 67.8