Revenue from Contracts with Customers - Net Revenue From External Customers and Intercompany Revenue From Each Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Disaggregation of Revenue [Line Items]
Net revenue	$ 934.4	$ 890.7	$ 1,577.0	$ 1,481.6
Disclosure of complimentary revenue	15.6	14.2	30.0	27.6
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	266.0	274.2	529.2	513.4
Other
Disaggregation of Revenue [Line Items]
Net revenue	0.1	0.1	0.1	0.1
External Customer
Disaggregation of Revenue [Line Items]
Net revenue	934.4	890.7	1,577.0	1,481.6
External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	183.2	170.3	285.2	271.7
External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	256.5	221.4	502.6	442.3
External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	172.5	177.4	174.6	180.7
External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	232.8	235.7	453.7	437.6
External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	89.4	85.9	160.9	149.3
Operating Segments | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	934.3	890.6	1,576.9	1,481.5
Operating Segments | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	183.2	170.3	285.2	271.7
Operating Segments | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	256.5	221.4	502.6	442.3
Operating Segments | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	172.5	177.4	174.6	180.7
Operating Segments | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	232.8	235.7	453.7	437.6
Operating Segments | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	89.3	85.8	160.8	149.2
Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	509.9	464.7	782.4	709.8
Operating Segments | Live and Historical | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	31.0	25.5	34.9	29.3
Operating Segments | Live and Historical | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	509.9	464.7	782.4	709.8
Operating Segments | Live and Historical | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	53.6	50.4	64.8	61.4
Operating Segments | Live and Historical | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	252.5	212.1	488.9	424.2
Operating Segments | Live and Historical | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	172.3	176.0	173.7	177.1
Operating Segments | Live and Historical | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	3.0	3.3	6.3	6.4
Operating Segments | Live and Historical | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	28.5	22.9	48.7	40.7
Operating Segments | Wagering Services and Solutions
Disaggregation of Revenue [Line Items]
Net revenue	158.4	151.7	265.3	258.3
Operating Segments | Wagering Services and Solutions | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	10.0	8.2	18.9	15.7
Operating Segments | Wagering Services and Solutions | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	158.4	151.7	265.3	258.3
Operating Segments | Wagering Services and Solutions | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	125.3	115.4	205.4	195.2
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	4.0	4.3	7.9	10.0
Operating Segments | Wagering Services and Solutions | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	29.1	32.0	52.0	53.1
Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	266.0	274.2	529.2	513.4
Operating Segments | Gaming | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	0.3	0.2	4.3	4.2
Operating Segments | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	266.0	274.2	529.2	513.4
Operating Segments | Gaming | External Customer | Pari-mutuel, live and simulcast racing
Disaggregation of Revenue [Line Items]
Net revenue	4.3	4.5	15.0	15.1
Operating Segments | Gaming | External Customer | Pari-mutuel, historical racing
Disaggregation of Revenue [Line Items]
Net revenue	4.0	9.3	13.7	18.1
Operating Segments | Gaming | External Customer | Racing event-related services
Disaggregation of Revenue [Line Items]
Net revenue	0.2	1.4	0.9	3.6
Operating Segments | Gaming | External Customer | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	225.8	228.1	439.5	421.2
Operating Segments | Gaming | External Customer | Other
Disaggregation of Revenue [Line Items]
Net revenue	31.7	30.9	60.1	55.4
All Other
Disaggregation of Revenue [Line Items]
Net revenue	0.1	0.1	0.1	0.1
All Other | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	2.2	1.8	4.2	1.8
All Other | External Customer
Disaggregation of Revenue [Line Items]
Net revenue	0.1	0.1	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	0.1	0.1	0.1	0.1
Eliminations | Related Party
Disaggregation of Revenue [Line Items]
Net revenue	(43.5)	(35.7)	(62.3)	(51.0)
Churchill Downs Racetrack | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	227.5	228.0	231.1	231.1
Louisville | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	57.2	53.1	109.4	106.8
Northern Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	26.7	22.0	57.9	50.5
Southwestern Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	43.4	40.2	83.9	78.8
Western Kentucky | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	16.0	6.1	28.4	12.9
Virginia | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	136.0	111.9	265.3	223.1
New Hampshire | Operating Segments | Live and Historical
Disaggregation of Revenue [Line Items]
Net revenue	3.1	3.4	6.4	6.6
Florida | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	25.3	26.5	50.6	52.6
Iowa | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	23.7	23.5	47.2	46.9
Indiana | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	32.6	33.9	64.2	33.9
Louisiana | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	31.9	37.1	76.5	81.4
Maine | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	27.0	26.8	52.0	53.6
Maryland | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	25.6	26.2	46.4	47.8
Mississippi | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	24.0	24.5	49.1	50.5
New York | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	47.6	46.5	91.0	91.5
Pennsylvania | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Net revenue	$ 28.3	$ 29.2	$ 52.2	$ 55.2