Long-term Employee Benefits - Schedule of Fair Value of Defined Benefit Pension Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 134.1	$ 151.7	$ 158.0
Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	123.8	126.9	135.7
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.3	13.6	13.5
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	356.9	332.3	$ 365.0
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	156.9	129.7
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	30.4	32.9
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	134.1	151.7
Pension Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	321.4	314.3
Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	35.5	19.5
Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.0	4.5
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.0	4.4
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.1
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Pension Plan [Member] | US Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	36.0	23.7
Pension Plan [Member] | US Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	35.7	23.4
Pension Plan [Member] | US Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Pension Plan [Member] | US Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.3	0.3
Pension Plan [Member] | Non-US Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	45.8	42.9
Pension Plan [Member] | Non-US Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	42.9	39.9
Pension Plan [Member] | Non-US Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.4	1.0
Pension Plan [Member] | Non-US Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.5	2.0
Pension Plan [Member] | Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	69.6	70.9
Pension Plan [Member] | Government Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	45.0	41.1
Pension Plan [Member] | Government Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19.9	23.3
Pension Plan [Member] | Government Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.7	6.5
Pension Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	40.2	29.1
Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28.3	19.7
Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9.4	7.0
Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.5	2.4
Pension Plan [Member] | Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	125.8	129.6
Pension Plan [Member] | Private Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.0	1.2
Pension Plan [Member] | Private Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.7	1.5
Pension Plan [Member] | Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 124.1	126.9
Pension Plan [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		13.6
Pension Plan [Member] | Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
Pension Plan [Member] | Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
Pension Plan [Member] | Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		13.6
Pension Plan [Member] | Pension Trust Liability [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ (1.5)