Pension and Other Post-Retirement Benefit Plans (Pension Plan Assets Measured At Fair Value) (Details) - Pensions - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total pension plan assets, percent		99.00%
International
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		$ 657.8	$ 570.6	$ 699.2
International | Fair value, measurements, recurring
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		659.7	569.8
International | Fair value, measurements, recurring | Cash and cash equivalents
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		10.0	11.1
International | Fair value, measurements, recurring | U.S. companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		70.4	92.2
International | Fair value, measurements, recurring | International companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		251.5	186.8
International | Fair value, measurements, recurring | Registered investment companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets	[1]	63.4	44.4
International | Fair value, measurements, recurring | Common/collective trusts
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets	[1]		10.0
International | Fair value, measurements, recurring | Insurance contracts
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		138.5	125.0
International | Fair value, measurements, recurring | Hedge funds
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets	[1]	82.0	99.1
International | Fair value, measurements, recurring | Limited partnerships
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets	[1]	7.9
International | Fair value, measurements, recurring | Real estate and other investments
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		36.0	1.2
International | Fair value, measurements, recurring | Level 1
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		367.9	291.3
International | Fair value, measurements, recurring | Level 1 | Cash and cash equivalents
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		10.0	11.1
International | Fair value, measurements, recurring | Level 1 | U.S. companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		70.4	92.2
International | Fair value, measurements, recurring | Level 1 | International companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		251.5	186.8
International | Fair value, measurements, recurring | Level 1 | Real estate and other investments
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		36.0	1.2
International | Fair value, measurements, recurring | Level 2
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		138.5	125.0
International | Fair value, measurements, recurring | Level 2 | Insurance contracts
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		138.5	125.0
International | Fair value, measurements, recurring | Level 3
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets			0.0
UNITED STATES
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		520.0	477.4
UNITED STATES | Fair value, measurements, recurring
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		520.0	477.4
UNITED STATES | Fair value, measurements, recurring | Cash and cash equivalents
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		50.5	46.8
UNITED STATES | Fair value, measurements, recurring | U.S. companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		110.3	109.4
UNITED STATES | Fair value, measurements, recurring | International companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		5.4	8.5
UNITED STATES | Fair value, measurements, recurring | Registered investment companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets	[1]	36.3	32.6
UNITED STATES | Fair value, measurements, recurring | Common/collective trusts
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets	[1]	12.5	11.7
UNITED STATES | Fair value, measurements, recurring | Hedge funds
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets	[1]	164.3	176.5
UNITED STATES | Fair value, measurements, recurring | Limited partnerships
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets	[1]	139.4	89.7
UNITED STATES | Fair value, measurements, recurring | Real estate and other investments
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		1.3	2.2
UNITED STATES | Fair value, measurements, recurring | Level 1
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		167.5	166.9
UNITED STATES | Fair value, measurements, recurring | Level 1 | Cash and cash equivalents
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		50.5	46.8
UNITED STATES | Fair value, measurements, recurring | Level 1 | U.S. companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		110.3	109.4
UNITED STATES | Fair value, measurements, recurring | Level 1 | International companies
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		5.4	8.5
UNITED STATES | Fair value, measurements, recurring | Level 1 | Real estate and other investments
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets		$ 1.3	2.2
UNITED STATES | Fair value, measurements, recurring | Level 2
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets			0.0
UNITED STATES | Fair value, measurements, recurring | Level 3
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Total plan assets			$ 0.0

[1] Certain investments that are measured at fair value using net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.