Components of Deferred Tax Assets (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred Tax Assets, Net [Abstract]
Postretirement/post-employment benefits	$ 23.1	$ 25.3
Deferred compensation	192.4	193.4
Pension costs	36.6	25.8
Basis differences in fixed assets	(80.2)	(67.5)
Rent	41.7	41.1
Interest	58.9	60.9
Accruals and reserves	17.2	29.4
Allowance for doubtful accounts	13.3	10.8
Basis differences in intangible assets	(405.0)	(408.2)
Investments in equity securities	(6.3)	(8.3)
Tax loss/tax credit carry forwards	354.6	354.5
Prepaid expenses	(2.9)	(2.3)
Deferred revenue	(32.0)	0.0
Other	44.3	60.3
Total deferred tax assets, net	255.7	315.2
Valuation allowance	(255.6)	(275.1)	$ (332.2)	$ (467.3)
Net deferred tax assets	$ 0.1	$ 40.1