Long-lived Assets (Schedule of Intangible Assets Subject to Amortization, Net) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Gross carrying amount	$ 4,237.1	$ 4,194.4
Accumulated amortization	(3,343.5)	(3,163.2)
Net carrying amount	893.6	1,031.2
Customer relationships
Property, Plant and Equipment [Line Items]
Gross carrying amount	3,726.1	3,673.1
Accumulated amortization	(3,091.6)	(2,914.2)
Net carrying amount	634.5	758.9
Other
Property, Plant and Equipment [Line Items]
Gross carrying amount	511.0	521.3
Accumulated amortization	(251.9)	(249.0)
Net carrying amount	$ 259.1	$ 272.3