Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Definite-Lived Intangible Assets, Gross Carrying Amount	$ 33.1	$ 32.1
Definite-Lived Intangible Assets, Accumulated Amortization	(16.6)	(14.1)
Definite-Lived Intangible Assets, Net Carrying Amount	16.5	18.0
Indefinite-lived Intangible Assets, Net Carrying Amount	338.2	246.0
Total intangible assets	354.7	$ 264.0
Contractual Rights [Member] | Online Wagering
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets, Net Carrying Amount	8.0
Contractual Rights [Member] | Presque Isle
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets, Net Carrying Amount	56.0
Contractual Rights [Member] | Presque Isle | Online Wagering
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets, Net Carrying Amount	$ 10.0