Pension and Other Retiree Benefits (Fair Value of Plan Assets) (Details) - Pension - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 141.1	$ 162.1	$ 150.5
U.S. | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		131.1	151.4
U.S. | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1.7	1.7
U.S. | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
U.S. | Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			94.8
U.S. | Mutual Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		77.1	94.8
U.S. | Mutual Funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			0.0
U.S. | Mutual Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			0.0
U.S. | Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		77.1
U.S. | Equity Funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
U.S. | Equity Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
U.S. | Exchange traded funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		54.0	56.6
U.S. | Exchange traded funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		54.0	56.6
U.S. | Exchange traded funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
U.S. | Exchange traded funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
U.S. | Common collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1.7	1.7
U.S. | Common collective trust funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
U.S. | Common collective trust funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1.7	1.7
U.S. | Common collective trust funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
U.S. | Multi-strategy hedge funds | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	8.3	9.0
International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		417.6	463.8	$ 302.7
International | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		68.7	121.1
International | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		307.4	291.0
International | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2.7	2.2
International | Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2.7	2.2
International | Cash and cash equivalents | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Cash and cash equivalents | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		65.7	102.0
International | Equity Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		65.7	102.0
International | Equity Funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Equity Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Exchange traded funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.3	16.9
International | Exchange traded funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.3	16.9
International | Exchange traded funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Exchange traded funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Foreign corporate debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		71.7	72.2
International | Foreign corporate debt securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Foreign corporate debt securities | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		71.7	72.2
International | Foreign corporate debt securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Multi-strategy hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		196.3	133.4
International | Multi-strategy hedge funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Multi-strategy hedge funds | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		196.3	133.4
International | Multi-strategy hedge funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Multi-strategy hedge funds | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	21.0	30.5
International | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		25.4	24.4
International | Insurance contracts | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Insurance contracts | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		25.4	24.4
International | Insurance contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Foreign government debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		14.0	61.0
International | Foreign government debt securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Foreign government debt securities | Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		14.0	61.0
International | Foreign government debt securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0
International | Real estate | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	$ 20.5	$ 21.2

[1] (4)Certain investments that are measured at fair value using the net asset value per share practical expedient have not been categorized in the fair value hierarchy. The fair value amounts presented in these tables are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the table that presents our defined benefit pension and post-retirement plans funded status.