Discontinued operations (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended				16 Months Ended
	Apr. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Apr. 30, 2015
Discontinued operations
Non-cash impairment charge of discontinued operations		$ 0.0	$ 0.0	$ 3.2
Proceeds from divestitures		0.0	0.0	13.6
Restructuring and acquisition-related costs		11.0
Income (loss) from discontinued operations, net of tax		$ 0.0	0.0	(2.6)
Pressure Sensitive Materials [Member]
Discontinued operations
Proceeds from divestitures	$ 13.6				$ 136.9	$ 150.5
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax				(3.7)
Discontinued Operation, Tax Effect of Discontinued Operation				(1.1)
Income (loss) from discontinued operations, net of tax				(2.6)
Healthcare Plant Closure [Member]
Discontinued operations
Restructuring and acquisition-related costs				$ 7.8
Expected Cash Payments for Plant Closure			$ 7.0