Restructuring (Restructuring Charges and Reconciliation) (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2018		Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period					$ 13.3		$ 1.5
Provision		$ 2.1		$ 12.3	6.8		13.8
Cash Expenditures					(6.6)		(2.7)
Non-cash Items/ Currency Change					(0.4)		0.4
Balance at End of Period		13.1		16.5	13.1		16.5
Employee termination costs(1)
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period					12.0		1.4
Provision					5.0		11.6
Cash Expenditures					(5.2)		(1.8)
Non-cash Items/ Currency Change					(0.3)		0.3
Balance at End of Period		11.5	[1]	12.9	$ 11.5	[1]	12.9
Restructuring and Related Costs, Payment Period					12 months
Termination of lease agreements(2)
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost Remaining		3.0			$ 3.0
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period					0.8		0.1
Provision					1.6		1.3
Cash Expenditures					(1.0)		(0.7)
Non-cash Items/ Currency Change					(0.1)		0.1
Balance at End of Period		1.3	[2]	2.8	$ 1.3	[2]	2.8
Restructuring and Related Costs, Payment Period					12 months
Other(3)
Restructuring Reserve [Roll Forward]
Balance at Beginning of Period					$ 0.5		0.0
Provision					0.2		0.9
Cash Expenditures					(0.4)		(0.2)
Non-cash Items/ Currency Change					0.0		0.0
Balance at End of Period		$ 0.3	[3]	$ 0.8	$ 0.3	[3]	0.8
Restructuring and Related Costs, Payment Period					6 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] (1) We expect the remaining $11.5 million employee termination costs to be substantially paid in the next twelve months.

[2] (2) We expect the remaining $1.3 million termination of lease costs to be substantially paid in the next twelve months.

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

[4] (4) Restructuring liabilities assumed in the Esselte Acquisition.