Long-lived Assets (Schedule of Intangible Assets Subject to Amortization, Net) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Gross carrying amount	$ 4,081.6	$ 4,194.4
Accumulated amortization	(3,262.3)	(3,163.2)
Net carrying amount	819.3	1,031.2
Customer relationships
Property, Plant and Equipment [Line Items]
Gross carrying amount	3,526.0	3,673.1
Accumulated amortization	(2,997.1)	(2,914.2)
Net carrying amount	528.9	758.9
Other
Property, Plant and Equipment [Line Items]
Gross carrying amount	555.6	521.3
Accumulated amortization	(265.2)	(249.0)
Net carrying amount	$ 290.4	$ 272.3