Restructuring (Restructuring Charges (Credits)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credits)	$ 21.7	$ 5.4	$ (0.4)
Operating Segments | ACCO Brands North America
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credits)	5.5	1.1	(0.4)
Operating Segments | ACCO Brands EMEA
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credits)	11.2	0.0	0.0
Operating Segments | ACCO Brands International
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credits)	$ 5.0	$ 4.3	$ 0.0