Goodwill And Indefinite-Lived Intangible Assets Impairment Test Intangible Table (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 179.2	$ 187.4
Finite-Lived Intangible Assets, Accumulated Amortization	(103.3)	(100.0)
Finite-Lived Intangible Assets, Net	75.9	87.4
Indefinite-Lived Intangible Assets (Excluding Goodwill)	358.3	358.3
Other intangible assets, net	434.2	$ 445.7
Customer Relationships [Member] | TwinSpires [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Period Increase (Decrease)	(15.1)
TwinSpires [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	9.2
Calder
Finite-Lived Intangible Assets [Line Items]
Annual License Fees	$ 2.3