Accounting Changes Pension and Post-Retirement Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 0.0	$ 0.0	$ (0.2)
Additions to Other Assets, Amount	413.9	0.0		$ 460.7
Operating Lease, Liability	432.3	0.0		$ 483.6
Reclassification out of Accumulated Other Comprehensive Income [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	0.0	$ 19.4	$ 0.0
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred Tax Assets, Deferred Gain on Sale Leaseback Transaction	$ 4.0