|**Goodwill**                                             | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
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|**Goodwill and Intangible Assets Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
|Goodwill                                                 | 6.  GOODWILLGoodwill, by segment, is comprised of the following:(in millions)Live and HistoricalTwinSpiresGamingAll OtherTotalBalance, December 31, 2021$52.4$152.2$161.2$1.0$366.8Additions227.9—129.1—357.0Balance, December 31, 2022280.3152.2290.31.0723.8Additions95.981.2——177.1Adjustments———(1.0)(1.0)Balance, December 31, 2023$376.2$233.4$290.3$—$899.9In 2022, we established goodwill of $9.2 million related to the Ellis Park Transaction and $347.8 million related to the P2E Transaction. The goodwill established as part of the P2E Transaction was assigned to the Gaming segment in the amount of $129.1 million and to the Live and Historical Racing segment in the amount of $218.7 million.In 2023, we established goodwill of $177.1 million related to the Exacta Transaction. The goodwill was assigned to the Live and Historical Racing segment in the amount of $95.9 million and to the TwinSpires segment in the amount of $81.2 million.Refer to Note 3, Acquisitions for more information on these transactions.We performed our annual goodwill impairment analysis as of April 1, 2023. We assessed goodwill for impairment by performing qualitative or quantitative analyses for each reporting unit. Based on the results of these analyses, no goodwill impairments were identified in connection with our annual impairment testing.
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|(in millions)                                            | Live and Historical                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|Balance, December 31, 2021                               | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
|Additions                                                | 227.9                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Balance, December 31, 2022                               | 280.3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Additions                                                | 95.9                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Adjustments                                              | —                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
|Balance, December 31, 2023                               | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
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