Loss from discontinued operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Adjustments to contingencies of former operations	$ (0.1)	$ 0.0
Income (loss) from discontinued operations before income taxes	(0.1)	0.0
Provision (benefit) for income taxes	(0.1)	0.0
Income (loss) from discontinued operations, net of tax	0.0	0.0
Revenues	788.4	721.8
Losses from operations before tax	$ 54.9	8.9
Ireland
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		3.6
Losses from operations before tax		$ 7.9