Revenue from Contracts with Customers - Net Revenue From External Customers and Intercompany Revenue From Each Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Net revenue	$ 590.9	$ 559.5
Disclosure of complimentary revenue	13.4	12.1
Related Party
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0
Gaming
Disaggregation of Revenue [Line Items]
Net revenue	239.2	250.0
Other
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.3
External Customer
Disaggregation of Revenue [Line Items]
Net revenue	590.9	559.5
External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	101.4	102.0
External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	220.9	191.3
External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	3.3	2.9
External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	201.9	212.5
External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	63.4	50.8
Operating Segments | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	590.9	559.2
Operating Segments | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	101.4	102.0
Operating Segments | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	220.9	191.3
Operating Segments | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	3.3	2.9
Operating Segments | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	201.9	212.5
Operating Segments | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	63.4	50.5
Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	245.1	214.4
Operating Segments | Live and Historical | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	3.8	1.4
Operating Segments | Live and Historical | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	245.1	214.4
Operating Segments | Live and Historical | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	11.0	11.0
Operating Segments | Live and Historical | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	212.1	185.3
Operating Segments | Live and Historical | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	1.1	1.0
Operating Segments | Live and Historical | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	3.1	2.6
Operating Segments | Live and Historical | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	17.8	14.5
Operating Segments | TwinSpires
Disaggregation of Revenue [Line Items]
Net revenue	106.6	94.8
Operating Segments | TwinSpires | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	7.5	1.6
Operating Segments | TwinSpires | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	106.6	94.8
Operating Segments | TwinSpires | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	79.8	79.4
Operating Segments | TwinSpires | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0
Operating Segments | TwinSpires | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0
Operating Segments | TwinSpires | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	5.7	4.4
Operating Segments | TwinSpires | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	21.1	11.0
Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	239.2	250.0
Operating Segments | Gaming | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	4.0	1.5
Operating Segments | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	239.2	250.0
Operating Segments | Gaming | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	10.6	11.6
Operating Segments | Gaming | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	8.8	6.0
Operating Segments | Gaming | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	2.2	1.9
Operating Segments | Gaming | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	193.1	205.5
Operating Segments | Gaming | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	24.5	25.0
All Other
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.3
All Other | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.2
All Other | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.3
All Other | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0
All Other | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0
All Other | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0
All Other | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0
All Other | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.3
Eliminations | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	(15.3)	(4.7)
Churchill Downs Racetrack | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	3.1	2.4
Louisville | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	53.7	44.0
Northern Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	28.5	26.3
Southwestern Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	38.6	36.5
Western Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	6.8	4.8
Virginia | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	111.2	97.7
New Hampshire | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	3.2	2.7
Florida | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	26.1	26.1
Iowa | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	23.4	24.5
Louisiana | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	44.3	44.1
Maine | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	26.8	27.7
Maryland | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	21.6	23.3
Mississippi | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	26.0	27.5
New York | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	45.0	44.5
Pennsylvania | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	$ 26.0	$ 32.3