Other Expense, Net - Components of Other Expense, Net (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset disposals and write-offs		$ (4.3)	$ (5.1)
Facilities closure and other costs	[1]		(0.1)
Other		(1.3)	(2.4)
Total		(6.0)	(8.3)
Wallula, Washington Mill
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	[2]	$ (0.4)	$ (0.7)

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

[2] Includes charges related to the discontinuation of production of uncoated free sheet and coated one-side grades at the Wallula, Washington mill in the second quarter of 2018 and the conversion of the No. 3 paper machine to a high-performance 100% virgin kraft linerboard machine.