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, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Net revenue	$ 559.5	$ 364.1
Intercompany net revenue	0.0	0.0
Disclosure of complimentary revenue	12.1	7.0
Gaming
Disaggregation of Revenue [Line Items]
Net revenue	250.0	177.3
Other
Disaggregation of Revenue [Line Items]
Net revenue	0.3	0.5
External Customer
Disaggregation of Revenue [Line Items]
Net revenue	559.5	364.1
External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	102.0	100.0
External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	191.3	73.6
External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	2.9	0.9
External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	212.5	161.2
External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	50.8	28.4
Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	215.8	87.2
TwinSpires
Disaggregation of Revenue [Line Items]
Net revenue	96.3	101.4
Gaming
Disaggregation of Revenue [Line Items]
Net revenue	251.6	179.2
Operating Segments | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	559.2	363.6
Operating Segments | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	102.0	100.0
Operating Segments | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	191.3	73.6
Operating Segments | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	2.9	0.9
Operating Segments | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	212.5	161.2
Operating Segments | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	50.5	27.9
Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	214.4	86.0
Intercompany net revenue	1.4	1.2
Operating Segments | Live and Historical | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	214.4	86.0
Operating Segments | Live and Historical | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	11.0	5.6
Operating Segments | Live and Historical | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	185.3	73.6
Operating Segments | Live and Historical | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	1.0	0.5
Operating Segments | Live and Historical | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	2.6	0.0
Operating Segments | Live and Historical | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	14.5	6.3
Operating Segments | TwinSpires
Disaggregation of Revenue [Line Items]
Net revenue	94.8	100.3
Intercompany net revenue	1.6	1.1
Operating Segments | TwinSpires | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	94.8	100.3
Operating Segments | TwinSpires | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	79.4	81.5
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	4.4	10.3
Operating Segments | TwinSpires | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	11.0	8.5
Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	250.0	177.3
Intercompany net revenue	1.5	1.9
Operating Segments | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	250.0	177.3
Operating Segments | Gaming | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	11.6	12.9
Operating Segments | Gaming | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	6.0	0.0
Operating Segments | Gaming | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	1.9	0.4
Operating Segments | Gaming | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	205.5	150.9
Operating Segments | Gaming | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	25.0	13.1
All Other
Disaggregation of Revenue [Line Items]
Net revenue	0.3	0.5
Intercompany net revenue	0.2	0.0
All Other | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	0.3	0.5
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	0.3	0.5
Eliminations
Disaggregation of Revenue [Line Items]
Intercompany net revenue	(4.7)	(4.2)
Churchill Downs Racetrack | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	2.4	2.0
Louisville | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	44.0	42.8
Northern Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	26.3	10.8
Southwestern Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	36.5	30.4
Western Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	4.8	0.0
Virginia | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	97.7	0.0
New Hampshire | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	2.7	0.0
Florida | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	26.1	27.0
Iowa | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	24.5	0.0
Louisiana | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	44.1	41.5
Maine | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	27.7	26.8
Maryland | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	23.3	21.3
Mississippi | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	27.5	27.5
New York | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	44.5	0.0
Pennsylvania | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	$ 32.3	$ 33.2