Revenue from Contracts with Customers - Net Revenue From External Customer and Intercompany Revenue From Each Operating Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total net revenue	$ 1,809.8	$ 1,597.2	$ 1,054.0
Intercompany net revenues	0.0	0.0	0.0
Other revenue	33.9	20.9	13.1
External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	1,809.8	1,597.2	1,054.0
Live and simulcast racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	462.3	502.6	475.1
Historical racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	383.9	253.0	93.6
Racing event-related services | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	131.6	76.7	24.7
Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	755.9	695.4	435.3
Gaming | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	679.1	656.8	392.6
All Other
Disaggregation of Revenue [Line Items]
Total net revenue	2.9	41.3	19.0
All Other | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	152.9	108.1	68.0
Live and Historical Racing
Disaggregation of Revenue [Line Items]
Total net revenue	646.4	430.6	188.8
TwinSpires
Disaggregation of Revenue [Line Items]
Total net revenue	441.6	457.8	435.6
Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	761.8	698.4	437.8
Operating Segments | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	1,806.9	1,555.9	1,035.0
Operating Segments | Live and simulcast racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	462.3	472.9	456.9
Operating Segments | Historical racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	383.9	253.0	93.6
Operating Segments | Racing event-related services | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	131.6	69.7	24.4
Operating Segments | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	679.1	656.8	392.6
Operating Segments | All Other | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	150.0	103.5	67.5
Operating Segments | Live and Historical Racing
Disaggregation of Revenue [Line Items]
Total net revenue	614.6	409.1	169.6
Intercompany net revenues	31.8	21.5	19.2
Operating Segments | Live and Historical Racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	614.6	409.1	169.6
Operating Segments | Live and Historical Racing | Live and simulcast racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	66.8	64.0	46.5
Operating Segments | Live and Historical Racing | Historical racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	374.1	253.0	93.6
Operating Segments | Live and Historical Racing | Racing event-related services | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	129.8	68.5	21.0
Operating Segments | Live and Historical Racing | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	3.5	0.0	0.0
Operating Segments | Live and Historical Racing | All Other | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	40.4	23.6	8.5
Operating Segments | TwinSpires
Disaggregation of Revenue [Line Items]
Total net revenue	436.4	451.4	430.1
Intercompany net revenues	5.2	6.4	5.5
Operating Segments | TwinSpires | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	436.4	451.4	430.1
Operating Segments | TwinSpires | Live and simulcast racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	367.4	380.7	387.5
Operating Segments | TwinSpires | Historical racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	0.0	0.0	0.0
Operating Segments | TwinSpires | Racing event-related services | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	0.0	0.0	0.0
Operating Segments | TwinSpires | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	28.2	34.8	11.3
Operating Segments | TwinSpires | All Other | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	40.8	35.9	31.3
Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Intercompany net revenues	5.9	3.0	2.5
Operating Segments | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	755.9	695.4	435.3
Operating Segments | Gaming | Live and simulcast racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	28.1	28.2	22.9
Operating Segments | Gaming | Historical racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	9.8	0.0	0.0
Operating Segments | Gaming | Racing event-related services | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	1.8	1.2	3.4
Operating Segments | Gaming | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	647.4	622.0	381.3
Operating Segments | Gaming | All Other | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	68.8	44.0	27.7
All Other
Disaggregation of Revenue [Line Items]
Total net revenue	2.9	41.3	19.0
Intercompany net revenues	0.4	7.9	7.8
All Other | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	2.9	41.3	19.0
All Other | Live and simulcast racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	0.0	29.7	18.2
All Other | Historical racing | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	0.0	0.0	0.0
All Other | Racing event-related services | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	0.0	7.0	0.3
All Other | Gaming | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	0.0	0.0	0.0
All Other | All Other | External Customer
Disaggregation of Revenue [Line Items]
Total net revenue	2.9	4.6	0.5
Eliminations
Disaggregation of Revenue [Line Items]
Intercompany net revenues	(43.3)	(38.8)	(35.0)
Churchill Downs Racetrack | Operating Segments | Live and Historical Racing
Disaggregation of Revenue [Line Items]
Total net revenue	196.8	128.1	63.3
Churchill Downs Racetrack | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	755.9	695.4	435.3
Louisville | Operating Segments | Live and Historical Racing
Disaggregation of Revenue [Line Items]
Total net revenue	169.9	154.3	79.5
Northern Kentucky | Operating Segments | Live and Historical Racing
Disaggregation of Revenue [Line Items]
Total net revenue	46.1	26.0	10.2
Southwestern Kentucky | Operating Segments | Live and Historical Racing
Disaggregation of Revenue [Line Items]
Total net revenue	131.4	100.7	16.6
Western Kentucky | Operating Segments | Live and Historical Racing
Disaggregation of Revenue [Line Items]
Total net revenue	4.5	0.0	0.0
Virginia | Operating Segments | Live and Historical Racing
Disaggregation of Revenue [Line Items]
Total net revenue	62.4	0.0	0.0
New Hampshire | Operating Segments | Live and Historical Racing
Disaggregation of Revenue [Line Items]
Total net revenue	3.5	0.0	0.0
Florida | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	106.2	100.0	51.8
Iowa | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	15.6	0.0	0.0
Louisiana | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	140.8	133.6	97.6
Maine | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	114.4	99.8	44.9
Maryland | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	105.3	100.6	60.2
Mississippi | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	101.8	117.3	87.0
New York | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	30.9	0.0	0.0
Pennsylvania | Operating Segments | Gaming
Disaggregation of Revenue [Line Items]
Total net revenue	$ 140.9	$ 144.1	$ 93.8