Income Taxes Change in Valuation Allowances (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary of Valuation Allowances
Beginning balance		$ 255.6	$ 275.1	$ 332.2
Reversed to costs and expenses		(4.6)	(15.4)	(20.8)
(Reversed) charged to gross tax assets and other accounts 1	[1]	(27.0)	9.5	(9.2)
Foreign currency translation		19.3	(13.6)	(27.1)
Ending balance		243.3	255.6	$ 275.1
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Operating Loss Carryforwards		1,186.8
Deferred Tax Liabilities, Undistributed Foreign Earnings		2,774.8	$ 2,622.4
Foreign Tax Authority
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration		656.6
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		530.2
State and Local Jurisdiction [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		$ 45.0
Minimum | Foreign Tax Authority
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Operating Loss Carryforwards, Expiration Date		Jan. 01, 2018
Minimum | State and Local Jurisdiction [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Operating Loss Carryforwards, Expiration Date		Jan. 01, 2018
Maximum | Foreign Tax Authority
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Operating Loss Carryforwards, Expiration Date		Jan. 01, 2037
Maximum | State and Local Jurisdiction [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Operating Loss Carryforwards, Expiration Date		Jan. 01, 2037

[1] Primarily represents changes to the valuation allowance related to the change of a corresponding deferred tax asset.