Fair Value Measurements Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Millions		Sep. 30, 2020	Dec. 31, 2019
Financial Assets
Derivative Asset, Netting Adjustments	[1]	$ (11.6)	$ 0.0
Assets, Fair Value Disclosure		101.9	24.8
Financial liabilities
Derivative Liability, Netting Adjustments	[1]	(11.6)	0.0
Financial Liabilities Fair Value Disclosure		36.4	46.0
Rabbi Trust Marketable Securities		23.6	23.1
WRAP Plan Liabilities		25.0	26.8
Level 1 [Member]
Financial Assets
Assets, Fair Value Disclosure		23.6	23.1
Financial liabilities
Financial Liabilities Fair Value Disclosure		25.0	26.8
Fair Value, Inputs, Level 2 [Member]
Financial Assets
Assets, Fair Value Disclosure		89.9	1.7
Financial liabilities
Financial Liabilities Fair Value Disclosure		23.0	19.2
Level 3 [Member]
Financial Assets
Assets, Fair Value Disclosure		0.0	0.0
Financial liabilities
Financial Liabilities Fair Value Disclosure		0.0	0.0
Long-term [Member]
Financial Assets
Derivative Asset, Netting Adjustments	[1]	(0.1)	0.0
Investments, Fair Value Disclosure		23.6	23.1
Derivative Asset, Net		0.8	0.2
Financial liabilities
Derivative Liability, Netting Adjustments	[1]	(0.1)	0.0
Fair value of deferred compensation liabilities - long-term		25.0	26.8
Derivative Liability, Net		6.7	0.5
Long-term [Member] | Level 1 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0.0	0.0
Financial liabilities
Derivative Liability, Fair Value, Gross		0.0	0.0
Long-term [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0.9	0.2
Financial liabilities
Derivative Liability, Fair Value, Gross		6.8	0.5
Long-term [Member] | Level 3 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0.0	0.0
Financial liabilities
Derivative Liability, Fair Value, Gross		0.0	0.0
Short-term [Member]
Financial Assets
Derivative Asset, Netting Adjustments	[1]	(11.5)	0.0
Derivative Asset, Net		77.5	1.5
Financial liabilities
Derivative Liability, Netting Adjustments	[1]	(11.5)	0.0
Derivative Liability, Net		4.7	18.7
Short-term [Member] | Level 1 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0.0	0.0
Financial liabilities
Derivative Liability, Fair Value, Gross		0.0	0.0
Short-term [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		89.0	1.5
Financial liabilities
Derivative Liability, Fair Value, Gross		16.2	18.7
Short-term [Member] | Level 3 [Member]
Financial Assets
Derivative Asset, Fair Value, Gross		0.0	0.0
Financial liabilities
Derivative Liability, Fair Value, Gross		$ 0.0	$ 0.0

[1] The Company nets its derivative contract assets and liabilities outstanding with the same counterparty on the balance sheets for the contracts that contain netting provisions. Refer to Note 7 – Derivative Contracts for additional information regarding the Company's derivative contracts.