Leases Schedule of Prospective Adoption of New Accounting Pronouncements (Details) - USD ($) $ in Millions	Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2018
Leases, Initial Application Period Cumulative Effect Transition [Line Items]
Operating Lease, Right-of-Use Asset	$ 192.1	[1]	$ 241.1	$ 0.0
Finance Lease, Right-of-Use Asset	423.2		340.9	340.9
Operating Lease, Liability	$ 194.1		241.1	0.0
Capital Lease Obligations			302.2	$ 302.2
Accounting Standards Update 2016-02
Leases, Initial Application Period Cumulative Effect Transition [Line Items]
Operating Lease, Right-of-Use Asset			241.1
Finance Lease, Right-of-Use Asset			0.0
Operating Lease, Liability			241.1
Capital Lease Obligations			$ 0.0

[1] We adopted ASC 842 effective January 1, 2019, with an immaterial, cumulative-effect adjustment to the opening balance of retained earnings as of that date. As allowed under the standard, we have not changed our accounting and reporting for lease arrangements for periods presented prior to January 1, 2019. See Note 4 to the Consolidated Financial Statements for additional information on the impact to our Consolidated Balance Sheets.