Components of Deferred Tax Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets, Net [Abstract]
Postretirement/post-employment benefits	$ 17.9	$ 19.5
Deferred compensation	99.8	91.7
Pension costs	22.2	27.6
Basis differences in fixed assets	(71.7)	(52.0)
Rent	27.3	27.5
Interest	48.8	45.8
Accruals and reserves	21.0	18.4
Allowance for doubtful accounts	7.4	10.2
Basis differences in intangible assets	(302.7)	(281.3)
Investments in equity securities	1.2	(3.3)
Tax loss/tax credit carry forwards	345.6	357.9
Prepaid expenses	(6.3)	(1.7)
Deferred revenue	(26.8)	(41.3)
Unremitted foreign earnings	(9.5)	0.0
Other	38.2	43.7
Total deferred tax assets, net	212.4	262.7
Valuation allowance	(211.0)	(243.0)	$ (255.6)	$ (275.1)
Net deferred tax assets	$ 1.4	$ 19.7