Basis of Presentation Pension and Post-Retirement Benefits (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
	Jan. 01, 2019	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use assets		$ 466.2			$ 16.8
Lease liability		467.3			$ 11.3
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
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use assets	$ 460.7
Lease liability	483.6
Deferred gain recognized	$ 39.4
Scenario, Forecast [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred gain recognized				$ 4.0