Segment Information - Schedule of Net Revenue from External Customers (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 364.1	$ 324.3
Intercompany net revenue	0.0	0.0
Disclosure of complimentary revenue	7.0	3.7
Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	87.2	64.7
TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	101.4	105.0
Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	179.2	154.0
Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	364.1	324.3
Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	86.0	63.2
Intercompany net revenue	1.2	1.5
Operating Segments | Live and Historical Racing | Churchill Downs Racetrack
Segment Reporting Information [Line Items]
Net revenue from external customers	2.0	2.0
Operating Segments | Live and Historical Racing | Derby City Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	42.8	32.9
Operating Segments | Live and Historical Racing | Oak Grove
Segment Reporting Information [Line Items]
Net revenue from external customers	30.4	19.4
Operating Segments | Live and Historical Racing | Turfway Park
Segment Reporting Information [Line Items]
Net revenue from external customers	4.5	4.5
Operating Segments | Live and Historical Racing | Newport
Segment Reporting Information [Line Items]
Net revenue from external customers	6.3	4.4
Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	100.3	103.5
Intercompany net revenue	1.1	1.5
Operating Segments | TwinSpires | Horse Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	90.0	96.5
Operating Segments | TwinSpires | Sports and Casino
Segment Reporting Information [Line Items]
Net revenue from external customers	10.3	7.0
Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	177.3	152.0
Intercompany net revenue	1.9	2.0
Operating Segments | Gaming | Fair Grounds and VSI
Segment Reporting Information [Line Items]
Net revenue from external customers	41.5	38.3
Operating Segments | Gaming | Presque Isle
Segment Reporting Information [Line Items]
Net revenue from external customers	27.2	23.8
Operating Segments | Gaming | Ocean Downs
Segment Reporting Information [Line Items]
Net revenue from external customers	21.3	20.0
Operating Segments | Gaming | Calder
Segment Reporting Information [Line Items]
Net revenue from external customers	27.0	20.9
Operating Segments | Gaming | Oxford
Segment Reporting Information [Line Items]
Net revenue from external customers	26.8	15.7
Operating Segments | Gaming | Riverwalk
Segment Reporting Information [Line Items]
Net revenue from external customers	14.4	14.4
Operating Segments | Gaming | Harlow’s
Segment Reporting Information [Line Items]
Net revenue from external customers	13.1	14.0
Operating Segments | Gaming | Lady Luck Nemacolin
Segment Reporting Information [Line Items]
Net revenue from external customers	6.0	4.9
All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.5	5.6
Intercompany net revenue	0.0	1.6
Eliminations
Segment Reporting Information [Line Items]
Intercompany net revenue	(4.2)	(6.6)
Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	177.3	152.0
Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.5	5.6
External Customer
Segment Reporting Information [Line Items]
Net revenue from external customers	364.1	324.3
External Customer | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	363.6	318.7
External Customer | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	86.0	63.2
External Customer | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	100.3	103.5
External Customer | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	177.3	152.0
External Customer | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.5	5.6
External Customer | Pari-mutuel, live and simulcast racing
Segment Reporting Information [Line Items]
Net revenue from external customers	100.0	111.9
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	100.0	106.8
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	5.6	5.9
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	81.5	89.2
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	12.9	11.7
External Customer | Pari-mutuel, live and simulcast racing | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	5.1
External Customer | Pari-mutuel, historical racing
Segment Reporting Information [Line Items]
Net revenue from external customers	73.6	52.9
External Customer | Pari-mutuel, historical racing | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	73.6	52.9
External Customer | Pari-mutuel, historical racing | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	73.6	52.9
External Customer | Pari-mutuel, historical racing | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0
External Customer | Pari-mutuel, historical racing | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0
External Customer | Pari-mutuel, historical racing | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0
External Customer | Racing event-related services
Segment Reporting Information [Line Items]
Net revenue from external customers	0.9	0.7
External Customer | Racing event-related services | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	0.9	0.7
External Customer | Racing event-related services | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	0.5	0.0
External Customer | Racing event-related services | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0
External Customer | Racing event-related services | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	0.4	0.7
External Customer | Racing event-related services | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0
External Customer | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	161.2	139.5
External Customer | Gaming | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	161.2	139.5
External Customer | Gaming | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0
External Customer | Gaming | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	10.3	7.0
External Customer | Gaming | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	150.9	132.5
External Customer | Gaming | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0
External Customer | Other
Segment Reporting Information [Line Items]
Net revenue from external customers	28.4	19.3
External Customer | Other | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	27.9	18.8
External Customer | Other | Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	6.3	4.4
External Customer | Other | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	8.5	7.3
External Customer | Other | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	13.1	7.1
External Customer | Other | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 0.5	$ 0.5