Information on Business Segments (Identifiable Intangibles and Goodwill by Segment) (Details) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Assets Including Allocation of Identifiable Intangible Assets and Goodwill		$ 2,786.4	$ 2,799.1
Operating Segments
Segment Reporting Information [Line Items]
Assets Including Allocation of Identifiable Intangible Assets and Goodwill		2,570.0	2,550.0
Unallocated Assets
Segment Reporting Information [Line Items]
Assets Including Allocation of Identifiable Intangible Assets and Goodwill		215.1	248.3
Corporate
Segment Reporting Information [Line Items]
Assets Including Allocation of Identifiable Intangible Assets and Goodwill	[1]	1.3	0.8
ACCO Brands North America | Operating Segments
Segment Reporting Information [Line Items]
Assets Including Allocation of Identifiable Intangible Assets and Goodwill	[1]	1,231.0	1,204.3
ACCO Brands EMEA | Operating Segments
Segment Reporting Information [Line Items]
Assets Including Allocation of Identifiable Intangible Assets and Goodwill	[1]	709.2	711.7
ACCO Brands International | Operating Segments
Segment Reporting Information [Line Items]
Assets Including Allocation of Identifiable Intangible Assets and Goodwill	[1]	$ 629.8	$ 634.0

[1] Represents total assets, excluding intercompany balances, cash, deferred taxes, derivatives, prepaid pension assets and prepaid debt issuance costs.