Segment Information - Schedule of Net Revenue from External Customers (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 582.5	$ 515.1	$ 946.6	$ 839.4
Intercompany net revenue	0.0	0.0	0.0	0.0
Disclosure of complimentary revenue	7.7	5.2	14.8	8.9
Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	275.9	190.5	363.1	255.2
TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	138.5	142.6	239.9	247.6
Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	184.5	186.0	363.7	340.0
Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	582.5	515.1	946.6	839.4
Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	260.9	175.9	346.9	239.1
Intercompany net revenue	15.0	14.6	16.2	16.1
Operating Segments | Live and Historical Racing | Churchill Downs Racetrack
Segment Reporting Information [Line Items]
Net revenue from external customers	174.2	105.2	176.2	107.2
Operating Segments | Live and Historical Racing | Derby City Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	44.2	39.9	87.0	72.8
Operating Segments | Live and Historical Racing | Oak Grove
Segment Reporting Information [Line Items]
Net revenue from external customers	34.1	25.6	64.5	45.0
Operating Segments | Live and Historical Racing | Turfway Park
Segment Reporting Information [Line Items]
Net revenue from external customers	1.0	0.7	5.5	5.2
Operating Segments | Live and Historical Racing | Newport
Segment Reporting Information [Line Items]
Net revenue from external customers	7.4	4.5	13.7	8.9
Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	136.8	140.8	237.1	244.3
Intercompany net revenue	1.7	1.8	2.8	3.3
Operating Segments | TwinSpires | Horse Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	130.6	132.4	220.6	228.9
Operating Segments | TwinSpires | Sports and Casino
Segment Reporting Information [Line Items]
Net revenue from external customers	6.2	8.4	16.5	15.4
Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	184.3	186.0	361.6	338.0
Intercompany net revenue	0.2	0.0	2.1	2.0
Operating Segments | Gaming | Fair Grounds and VSI
Segment Reporting Information [Line Items]
Net revenue from external customers	37.2	35.1	78.7	73.4
Operating Segments | Gaming | Presque Isle
Segment Reporting Information [Line Items]
Net revenue from external customers	30.3	30.5	57.5	54.3
Operating Segments | Gaming | Ocean Downs
Segment Reporting Information [Line Items]
Net revenue from external customers	27.4	27.0	48.7	47.0
Operating Segments | Gaming | Calder
Segment Reporting Information [Line Items]
Net revenue from external customers	27.9	27.4	54.9	48.3
Operating Segments | Gaming | Oxford
Segment Reporting Information [Line Items]
Net revenue from external customers	29.4	24.6	56.2	40.3
Operating Segments | Gaming | Riverwalk
Segment Reporting Information [Line Items]
Net revenue from external customers	14.0	18.4	28.4	32.8
Operating Segments | Gaming | Harlow’s
Segment Reporting Information [Line Items]
Net revenue from external customers	12.0	16.6	25.1	30.6
Operating Segments | Gaming | Lady Luck Nemacolin
Segment Reporting Information [Line Items]
Net revenue from external customers	6.1	6.4	12.1	11.3
All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.5	12.4	1.0	18.0
Intercompany net revenue	0.0	2.4	0.0	4.0
Eliminations
Segment Reporting Information [Line Items]
Intercompany net revenue	(16.9)	(18.8)	(21.1)	(25.4)
Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	184.3	186.0	361.6	338.0
Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.5	12.4	1.0	18.0
External Customer
Segment Reporting Information [Line Items]
Net revenue from external customers	582.5	515.1	946.6	839.4
External Customer | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	582.0	502.7	945.6	821.4
External Customer | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	260.9	175.9	346.9	239.1
External Customer | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	136.8	140.8	237.1	244.3
External Customer | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	184.3	186.0	361.6	338.0
External Customer | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.5	12.4	1.0	18.0
External Customer | Pari-mutuel, live and simulcast racing
Segment Reporting Information [Line Items]
Net revenue from external customers	170.4	175.1	270.4	287.0
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	170.4	165.6	270.4	272.4
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	46.5	39.6	52.1	45.5
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	118.4	121.6	199.9	210.8
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	5.5	4.4	18.4	16.1
External Customer | Pari-mutuel, live and simulcast racing | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	9.5	0.0	14.6
External Customer | Pari-mutuel, historical racing
Segment Reporting Information [Line Items]
Net revenue from external customers	79.7	64.9	153.3	117.8
External Customer | Pari-mutuel, historical racing | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	79.7	64.9	153.3	117.8
External Customer | Pari-mutuel, historical racing | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	78.4	64.9	152.0	117.8
External Customer | Pari-mutuel, historical racing | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0	0.0	0.0
External Customer | Pari-mutuel, historical racing | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	1.3	0.0	1.3	0.0
External Customer | Pari-mutuel, historical racing | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0	0.0	0.0
External Customer | Racing event-related services
Segment Reporting Information [Line Items]
Net revenue from external customers	122.1	65.6	123.0	66.3
External Customer | Racing event-related services | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	122.1	63.7	123.0	64.4
External Customer | Racing event-related services | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	121.9	63.5	122.4	63.5
External Customer | Racing event-related services | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0	0.0	0.0
External Customer | Racing event-related services | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	0.2	0.2	0.6	0.9
External Customer | Racing event-related services | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	1.9	0.0	1.9
External Customer | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	164.3	178.6	325.5	318.1
External Customer | Gaming | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	164.3	178.6	325.5	318.1
External Customer | Gaming | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0	0.0	0.0
External Customer | Gaming | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	6.2	8.4	16.5	15.4
External Customer | Gaming | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	158.1	170.2	309.0	302.7
External Customer | Gaming | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0	0.0	0.0
External Customer | Other
Segment Reporting Information [Line Items]
Net revenue from external customers	46.0	30.9	74.4	50.2
External Customer | Other | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	45.5	29.9	73.4	48.7
External Customer | Other | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	14.1	7.9	20.4	12.3
External Customer | Other | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	12.2	10.8	20.7	18.1
External Customer | Other | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	19.2	11.2	32.3	18.3
External Customer | Other | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 0.5	$ 1.0	$ 1.0	$ 1.5