Segment Information - Net Revenue From External Customers and Intercompany Revenue From Each Operating Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total net revenue	$ 1,809.8	$ 1,597.2	$ 1,054.0
Live and Historical Racing
Segment Reporting Information [Line Items]
Total net revenue	646.4	430.6	188.8
TwinSpires
Segment Reporting Information [Line Items]
Total net revenue	441.6	457.8	435.6
Gaming
Segment Reporting Information [Line Items]
Total net revenue	761.8	698.4	437.8
External Customer
Segment Reporting Information [Line Items]
Total net revenue	1,809.8	1,597.2	1,054.0
Operating Segments | Live and Historical Racing
Segment Reporting Information [Line Items]
Total net revenue	614.6	409.1	169.6
Operating Segments | TwinSpires
Segment Reporting Information [Line Items]
Total net revenue	436.4	451.4	430.1
Operating Segments | External Customer
Segment Reporting Information [Line Items]
Total net revenue	1,806.9	1,555.9	1,035.0
Operating Segments | External Customer | Live and Historical Racing
Segment Reporting Information [Line Items]
Total net revenue	614.6	409.1	169.6
Operating Segments | External Customer | TwinSpires
Segment Reporting Information [Line Items]
Total net revenue	436.4	451.4	430.1
Operating Segments | External Customer | Gaming
Segment Reporting Information [Line Items]
Total net revenue	755.9	695.4	435.3
All Other
Segment Reporting Information [Line Items]
Total net revenue	2.9	41.3	19.0
All Other | External Customer
Segment Reporting Information [Line Items]
Total net revenue	$ 2.9	$ 41.3	$ 19.0