Revenue from Contracts with Customers - Net Revenue From External Customers and Intercompany Revenue From Each Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Disaggregation of Revenue [Line Items]
Net revenue	$ 683.0	$ 628.5	$ 2,260.0	$ 2,110.1
Disclosure of complimentary revenue	15.2	14.2	45.2	41.7
Related Party
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.0	0.0
Gaming
Disaggregation of Revenue [Line Items]
Net revenue	265.0	269.7	794.2	783.1
Other
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.1	0.1
External Customer
Disaggregation of Revenue [Line Items]
Net revenue	683.0	628.5	2,260.0	2,110.1
External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	108.1	102.9	393.3	374.6
External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	252.6	215.2	755.2	657.5
External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	4.2	6.4	178.8	187.1
External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	238.4	231.8	692.1	669.4
External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	79.7	72.2	240.6	221.5
Operating Segments | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	683.0	628.5	2,259.9	2,110.0
Operating Segments | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	108.1	102.9	393.3	374.6
Operating Segments | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	252.6	215.2	755.2	657.5
Operating Segments | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	4.2	6.4	178.8	187.1
Operating Segments | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	238.4	231.8	692.1	669.4
Operating Segments | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	79.7	72.2	240.5	221.4
Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	300.0	247.5	1,082.4	957.3
Operating Segments | Live and Historical | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	5.7	4.9	40.6	34.2
Operating Segments | Live and Historical | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	300.0	247.5	1,082.4	957.3
Operating Segments | Live and Historical | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	16.4	15.2	81.2	76.6
Operating Segments | Live and Historical | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	252.6	205.9	741.5	630.1
Operating Segments | Live and Historical | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	4.1	5.0	177.8	182.1
Operating Segments | Live and Historical | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	3.4	3.1	9.7	9.5
Operating Segments | Live and Historical | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	23.5	18.3	72.2	59.0
Operating Segments | Wagering Services and Solutions
Disaggregation of Revenue [Line Items]
Net revenue	118.0	111.3	383.3	369.6
Operating Segments | Wagering Services and Solutions | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	9.2	7.4	28.1	23.1
Operating Segments | Wagering Services and Solutions | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	118.0	111.3	383.3	369.6
Operating Segments | Wagering Services and Solutions | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	86.7	82.7	292.1	277.9
Operating Segments | Wagering Services and Solutions | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.0	0.0
Operating Segments | Wagering Services and Solutions | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.0	0.0
Operating Segments | Wagering Services and Solutions | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	4.7	4.4	12.6	14.4
Operating Segments | Wagering Services and Solutions | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	26.6	24.2	78.6	77.3
Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	265.0	269.7	794.2	783.1
Operating Segments | Gaming | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	0.5	0.6	4.8	4.8
Operating Segments | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	265.0	269.7	794.2	783.1
Operating Segments | Gaming | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	5.0	5.0	20.0	20.1
Operating Segments | Gaming | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	0.0	9.3	13.7	27.4
Operating Segments | Gaming | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	0.1	1.4	1.0	5.0
Operating Segments | Gaming | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	230.3	224.3	669.8	645.5
Operating Segments | Gaming | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	29.6	29.7	89.7	85.1
All Other
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.1	0.1
All Other | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	2.2	2.6	6.4	4.4
All Other | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.1	0.1
All Other | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.0	0.0
All Other | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.0	0.0
All Other | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.0	0.0
All Other | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.0	0.0
All Other | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	0.0	0.0	0.1	0.1
Eliminations | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	(17.6)	(15.5)	(79.9)	(66.5)
Churchill Downs Racetrack | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	11.9	11.7	243.0	242.8
Louisville | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	53.9	50.3	163.3	157.1
Northern Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	26.4	23.4	84.3	73.9
Southwestern Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	41.6	39.3	125.5	118.1
Western Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	21.8	9.8	50.2	22.7
Virginia | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	139.7	110.0	405.0	333.1
New Hampshire | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	4.7	3.0	11.1	9.6
Florida | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	23.4	23.8	74.0	76.4
Iowa | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	23.7	22.9	70.9	69.8
Indiana | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	33.3	32.4	97.5	66.3
Louisiana | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	26.1	32.0	102.6	113.4
Maine | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	28.9	27.7	80.9	81.3
Maryland | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	30.5	31.5	76.9	79.3
Mississippi | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	22.3	23.6	71.4	74.1
New York | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	48.0	46.8	139.0	138.3
Pennsylvania | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	$ 28.8	$ 29.0	$ 81.0	$ 84.2