Other Expense, Net - Components of Other Expense, Net (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset disposals and write-offs		$ (6.0)	$ (4.3)
Facilities closure and other costs	[1]	(0.4)
Other		(3.6)	(1.3)
Total		$ (10.0)	(6.0)
Wallula, Washington Mill
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	[2]		$ (0.4)

[1] Includes charges consisting of closure costs related to corrugated products facilities.

[2] Includes charges related to the second quarter 2018 discontinuation of uncoated free sheet and coated one-side grades at the Wallula, Washington mill associated with the conversion of the No. 3 paper machine to produce virgin kraft linerboard.