Pension, Post-Retirement and Post-Employment Plans - Fair Value of Plan Assets by Asset Category (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure
Total	$ 211.9	$ 189.0
Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure
Total	202.0	168.9
Assets using net asset value (or NAV) as a practical expedient
Defined Benefit Plan Disclosure
Total	9.9	20.1
Domestic equities | Level 1
Defined Benefit Plan Disclosure
Total	0.0	22.0
Derivatives | Level 2
Defined Benefit Plan Disclosure
Total	9.9	0.0
Foreign equities | Level 1
Defined Benefit Plan Disclosure
Total	5.4	3.9
Foreign bonds | Level 2
Defined Benefit Plan Disclosure
Total	1.3	0.0
Mutual funds holding U.S. Treasury Securities | Level 1
Defined Benefit Plan Disclosure
Total	20.3	19.0
Mutual funds holding fixed income securities | Level 1
Defined Benefit Plan Disclosure
Total	121.9	96.3
U.S. Treasury bonds | Level 2
Defined Benefit Plan Disclosure
Total	36.4	21.5
Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure
Total	$ 6.8	$ 6.2