Segment Information - Schedule of Net Revenue from External Customers (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 383.1	$ 393.0	$ 1,329.7	$ 1,232.4
Intercompany net revenue	0.0	0.0	0.0	0.0
Disclosure of complimentary revenue	8.4	6.1	23.2	15.0
Live and Historical Racing:
Segment Reporting Information [Line Items]
Net revenue from external customers	102.4	81.5	465.5	336.7
TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	107.4	109.0	347.3	356.6
Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	185.9	185.6	549.6	525.6
Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	383.1	393.0	1,329.7	1,232.4
Operating Segments | Live and Historical Racing:
Segment Reporting Information [Line Items]
Net revenue from external customers	92.3	79.7	439.2	318.8
Intercompany net revenue	10.1	1.8	26.3	17.9
Operating Segments | Live and Historical Racing: | Churchill Downs Racetrack
Segment Reporting Information [Line Items]
Net revenue from external customers	6.4	7.4	182.6	114.6
Operating Segments | Live and Historical Racing: | Derby City Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	41.5	40.2	128.5	113.0
Operating Segments | Live and Historical Racing: | Oak Grove
Segment Reporting Information [Line Items]
Net revenue from external customers	33.3	27.1	97.8	72.1
Operating Segments | Live and Historical Racing: | Turfway Park
Segment Reporting Information [Line Items]
Net revenue from external customers	3.1	0.7	8.6	5.9
Operating Segments | Live and Historical Racing: | Newport
Segment Reporting Information [Line Items]
Net revenue from external customers	6.9	4.3	20.6	13.2
Operating Segments | Live and Historical Racing: | Chasers
Segment Reporting Information [Line Items]
Net revenue from external customers	0.9	0.0	0.9	0.0
Operating Segments | Live and Historical Racing: | Ellis Park
Segment Reporting Information [Line Items]
Net revenue from external customers	0.2	0.0	0.2	0.0
Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	106.2	107.5	343.3	351.8
Intercompany net revenue	1.2	1.5	4.0	4.8
Operating Segments | TwinSpires | Horse Racing
Segment Reporting Information [Line Items]
Net revenue from external customers	100.9	98.8	321.5	327.7
Operating Segments | TwinSpires | Sports and Casino
Segment Reporting Information [Line Items]
Net revenue from external customers	5.3	8.7	21.8	24.1
Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	183.4	185.3	545.0	523.3
Intercompany net revenue	2.5	0.3	4.6	2.3
Operating Segments | Gaming | Fair Grounds and VSI
Segment Reporting Information [Line Items]
Net revenue from external customers	28.5	24.8	107.2	98.2
Operating Segments | Gaming | Presque Isle
Segment Reporting Information [Line Items]
Net revenue from external customers	33.2	35.9	90.7	90.2
Operating Segments | Gaming | Ocean Downs
Segment Reporting Information [Line Items]
Net revenue from external customers	33.3	31.7	82.0	78.7
Operating Segments | Gaming | Calder
Segment Reporting Information [Line Items]
Net revenue from external customers	26.3	25.9	81.2	74.2
Operating Segments | Gaming | Oxford
Segment Reporting Information [Line Items]
Net revenue from external customers	31.6	31.8	87.8	72.1
Operating Segments | Gaming | Riverwalk
Segment Reporting Information [Line Items]
Net revenue from external customers	12.6	14.5	41.0	47.3
Operating Segments | Gaming | Harlow’s
Segment Reporting Information [Line Items]
Net revenue from external customers	11.9	13.3	37.0	43.9
Operating Segments | Gaming | Lady Luck Nemacolin
Segment Reporting Information [Line Items]
Net revenue from external customers	6.0	7.4	18.1	18.7
All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	1.2	20.5	2.2	38.5
Intercompany net revenue	0.0	2.5	0.0	6.5
Eliminations
Segment Reporting Information [Line Items]
Intercompany net revenue	(13.8)	(6.1)	(34.9)	(31.5)
Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	183.4	185.3	545.0	523.3
Other
Segment Reporting Information [Line Items]
Net revenue from external customers	1.2	20.5	2.2	38.5
External Customer
Segment Reporting Information [Line Items]
Net revenue from external customers	383.1	393.0	1,329.7	1,232.4
External Customer | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	381.9	372.5	1,327.5	1,193.9
External Customer | Operating Segments | Live and Historical Racing:
Segment Reporting Information [Line Items]
Net revenue from external customers	92.3	79.7	439.2	318.8
External Customer | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	106.2	107.5	343.3	351.8
External Customer | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	183.4	185.3	545.0	523.3
External Customer | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	1.2	20.5	2.2	38.5
External Customer | Pari-mutuel, live and simulcast racing
Segment Reporting Information [Line Items]
Net revenue from external customers	96.4	112.3	366.8	399.3
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	96.4	99.7	366.8	372.1
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments | Live and Historical Racing:
Segment Reporting Information [Line Items]
Net revenue from external customers	1.8	5.4	53.9	50.9
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	91.0	89.4	290.9	300.2
External Customer | Pari-mutuel, live and simulcast racing | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	3.6	4.9	22.0	21.0
External Customer | Pari-mutuel, live and simulcast racing | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	12.6	0.0	27.2
External Customer | Pari-mutuel, historical racing
Segment Reporting Information [Line Items]
Net revenue from external customers	82.2	66.2	235.5	184.0
External Customer | Pari-mutuel, historical racing | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	82.2	66.2	235.5	184.0
External Customer | Pari-mutuel, historical racing | Operating Segments | Live and Historical Racing:
Segment Reporting Information [Line Items]
Net revenue from external customers	78.7	66.2	230.7	184.0
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	3.5	0.0	4.8	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	3.1	6.9	126.1	73.2
External Customer | Racing event-related services | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	3.1	1.9	126.1	66.3
External Customer | Racing event-related services | Operating Segments | Live and Historical Racing:
Segment Reporting Information [Line Items]
Net revenue from external customers	3.0	1.8	125.4	65.3
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	0.1	0.1	0.7	1.0
External Customer | Racing event-related services | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	5.0	0.0	6.9
External Customer | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	166.8	175.3	492.3	493.4
External Customer | Gaming | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	166.8	175.3	492.3	493.4
External Customer | Gaming | Operating Segments | Live and Historical Racing:
Segment Reporting Information [Line Items]
Net revenue from external customers	0.9	0.0	0.9	0.0
External Customer | Gaming | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	5.3	8.7	21.8	24.1
External Customer | Gaming | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	160.6	166.6	469.6	469.3
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	34.6	32.3	109.0	82.5
External Customer | Other | Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	33.4	29.4	106.8	78.1
External Customer | Other | Operating Segments | Live and Historical Racing:
Segment Reporting Information [Line Items]
Net revenue from external customers	7.9	6.3	28.3	18.6
External Customer | Other | Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue from external customers	9.9	9.4	30.6	27.5
External Customer | Other | Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue from external customers	15.6	13.7	47.9	32.0
External Customer | Other | All Other
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 1.2	$ 2.9	$ 2.2	$ 4.4