Restructuring, Impairment and Transaction-Related Charges (Restructuring Activities) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) facility	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Restructuring Cost and Reserve [Line Items]
Employee termination charges	$ 22.2	$ 23.0	$ 26.4
Integration costs	3.3	1.3	0.0
Other restructuring charges	4.4	44.6	18.4
Gains on the sale of facilities	8.4
Impairment charges	7.9	26.2	12.0
Impairment of machinery and equipment	7.6	16.6	6.7
Impairment of land and building	0.3	4.6	5.3
Impairment charges	7.9	26.2	12.0
Transaction-related charges	51.6	8.2	3.1
Non-cash adjustments/reclassifications	(15.1)	(61.2)
Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring liabilities	15.8
Accounts Payable
Restructuring Cost and Reserve [Line Items]
Restructuring liabilities	1.3
Other Noncurrent Liabilities
Restructuring Cost and Reserve [Line Items]
Long-term restructuring reserve	7.4
PERU
Restructuring Cost and Reserve [Line Items]
Impairment of machinery and equipment		5.0
Adjustment to MEPPs withdrawal liability
Restructuring Cost and Reserve [Line Items]
Other restructuring charges	32.1	32.1
Legal Costs | PERU
Restructuring Cost and Reserve [Line Items]
Other restructuring charges		10.0
Loss On Sale Of Business
Restructuring Cost and Reserve [Line Items]
Other restructuring charges			6.7
Gain From Settlement With Vendors
Restructuring Cost and Reserve [Line Items]
Gain on litigation settlement			(1.2)
Lease Liabilities
Restructuring Cost and Reserve [Line Items]
Non-cash adjustments/reclassifications	$ 2.0
2010 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Announced plant closures since inception | facility	45
LSC Communications
Restructuring Cost and Reserve [Line Items]
Transaction-related charges	$ 45.0	$ 6.4	$ 1.0