Segment Information - Net Revenue From External Customers and Intercompany Revenue From Each Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Net revenue	$ 572.5	$ 383.1	$ 1,900.5	$ 1,329.7
Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Net revenue	219.5	92.3	818.9	439.2
Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Net revenue	108.5	106.2	340.7	343.3
Operating Segments | Gaming
Segment Reporting Information [Line Items]
Net revenue	244.3	183.4	740.2	545.0
All Other
Segment Reporting Information [Line Items]
Net revenue	$ 0.2	$ 1.2	$ 0.7	$ 2.2