Business Segments - Geographic Information on Certain Long-Lived Assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Certain Long-Lived Assets	$ 8,269.0	$ 9,969.7	$ 8,432.1
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Certain Long-Lived Assets	6,395.7	8,003.9	6,634.3
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Certain Long-Lived Assets	1,702.5	1,761.2	1,644.6
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Certain Long-Lived Assets	$ 170.8	$ 204.6	$ 153.2