Goodwill And Intangible Assets, Net (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Goodwill and Intangible Assets [Line Items]
Goodwill	$ 1,529.8	$ 1,511.3
Franchise rights - indefinite-lived	603.7	589.4
Other intangibles	20.9	16.3
Other intangible assets, gross	624.6	605.7
Less: accumulated amortization	(8.3)	(7.5)
Other intangible assets, net	$ 616.3	$ 598.2