Restructuring (Restructuring Charges and Reconciliation) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018		Mar. 31, 2017
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period		$ 13.3		$ 1.5
Provision		4.7		1.5
Cash Expenditures		(3.4)		(0.6)
Non-cash Items/ Currency Change		0.2
Balance at End of Period		14.8		5.9
Employee termination costs(1)
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period		12.0		1.4
Provision		3.8		1.3
Cash Expenditures		(2.6)		(0.4)
Non-cash Items/ Currency Change		0.3
Balance at End of Period		$ 13.5	[1]	3.7
Restructuring and Related Costs, Payment Period		15 months
Termination of lease agreements(2)
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost Remaining		$ 2.4
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period		0.8		0.1
Provision		0.9		0.2
Cash Expenditures		(0.7)		(0.1)
Non-cash Items/ Currency Change		0.0
Balance at End of Period		$ 1.0	[2]	2.2
Restructuring and Related Costs, Payment Period		12 months
Other(3)
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost Remaining		$ 0.1
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period		0.5		0.0
Provision		0.0		0.0
Cash Expenditures		(0.1)		(0.1)
Non-cash Items/ Currency Change		(0.1)
Balance at End of Period		$ 0.3	[3]	0.0
Restructuring and Related Costs, Payment Period		9 months
Esselte Group Holdings AB
Restructuring Reserve [Roll Forward]
Acquisitions	[4]			3.5
Esselte Group Holdings AB | Employee termination costs(1)
Restructuring Reserve [Roll Forward]
Acquisitions				1.4
Esselte Group Holdings AB | Termination of lease agreements(2)
Restructuring Reserve [Roll Forward]
Acquisitions				2.0
Esselte Group Holdings AB | Other(3)
Restructuring Reserve [Roll Forward]
Acquisitions				$ 0.1

[1] We expect the remaining $13.5 million employee termination costs to be substantially paid in the next fifteen months.

[2] We expect the remaining $1.0 million termination of lease costs to be substantially paid in the next twelve months.

[3] We expect the remaining $0.3 million of other costs, principally contract exit costs, to be substantially paid in the next nine months.

[4] Restructuring liabilities assumed in the Esselte Acquisition.