|**Other Balance Sheet Items (Tables)**                     | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                         
|---------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**Receivables [Abstract]**                                 |                                                                                                                                                                                                                                                                                                                                                                                         
|Schedule of Accounts Receivable                            | Accounts receivable is comprised of the following:December 31,(in millions)20232022Trade receivables$42.6$12.5Simulcast and online wagering receivables44.954.1Other receivables24.420.6111.987.2Allowance for credit losses(5.0)(5.7)Total$106.9$81.5                                                                                                                                  
|                                                           |                                                                                                                                                                                                                                                                                                                                                                                         
|                                                           | December 31,                                                                                                                                                                                                                                                                                                                                                                            
|(in millions)                                              | 2023                                                                                                                                                                                                                                                                                                                                                                                    
|Trade receivables                                          | $                                                                                                                                                                                                                                                                                                                                                                                       
|Simulcast and online wagering receivables                  | 44.9                                                                                                                                                                                                                                                                                                                                                                                    
|Other receivables                                          | 24.4                                                                                                                                                                                                                                                                                                                                                                                    
|                                                           | 111.9                                                                                                                                                                                                                                                                                                                                                                                   
|Allowance for credit losses                                | (5.0)                                                                                                                                                                                                                                                                                                                                                                                   
|Total                                                      | $                                                                                                                                                                                                                                                                                                                                                                                       
|Schedule of Accrued Expenses and Other Current Liabilities | Accrued expenses and other current liabilities consisted of the following:December 31,(in millions)20232022Account wagering deposits liability$58.7$57.8Accrued salaries and related benefits45.139.6Purses payable35.246.1Accrued interest49.447.8Accrued fixed assets88.639.5Accrued gaming liabilities29.526.3Deferred payment on gaming rights50.650.6Other69.755.4Total$426.8$363.1
|                                                           |                                                                                                                                                                                                                                                                                                                                                                                         
|                                                           | December 31,                                                                                                                                                                                                                                                                                                                                                                            
|(in millions)                                              | 2023                                                                                                                                                                                                                                                                                                                                                                                    
|Account wagering deposits liability                        | $                                                                                                                                                                                                                                                                                                                                                                                       
|Accrued salaries and related benefits                      | 45.1                                                                                                                                                                                                                                                                                                                                                                                    
|Purses payable                                             | 35.2                                                                                                                                                                                                                                                                                                                                                                                    
|Accrued interest                                           | 49.4                                                                                                                                                                                                                                                                                                                                                                                    
|Accrued fixed assets                                       | 88.6                                                                                                                                                                                                                                                                                                                                                                                    
|Accrued gaming liabilities                                 | 29.5                                                                                                                                                                                                                                                                                                                                                                                    
|Deferred payment on gaming rights                          | 50.6                                                                                                                                                                                                                                                                                                                                                                                    
|Other                                                      | 69.7                                                                                                                                                                                                                                                                                                                                                                                    
|Total                                                      | $                                                                                                                                                                                                                                                                                                                                                                                       

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