Segment Information - Reconciliation of Comprehensive Income to Adjusted EBITDA by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Net income and comprehensive income	$ 155.7	$ 42.1
Depreciation and amortization	37.9	25.1
Interest expense	64.7	21.3
Income tax provision	53.2	16.5
EBITDA	311.5	105.0
Stock-based compensation expense	8.6	7.0
Pre-opening expense	3.2	2.1
Other expenses, net	3.7	2.5
Asset impairments	0.0	4.9
Transaction expense, net	(0.2)	5.0
Interest, depreciation and amortization expense related to equity investments	9.8	11.1
Changes in fair value of Rivers Des Plaines' interest rate swaps	0.0	(10.4)
Other charges and recoveries, net	0.3	1.0
Gain on sale of Arlington	(114.0)	0.0
Total adjustments to EBITDA	88.6	(23.5)
Adjusted EBITDA	222.9	128.5
Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	241.0	143.1
All Other
Segment Reporting Information [Line Items]
Adjusted EBITDA	(18.1)	(14.6)
Live and Historical
Segment Reporting Information [Line Items]
Adjusted EBITDA	82.1	27.9
Live and Historical | Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	82.1	27.9
TwinSpires
Segment Reporting Information [Line Items]
Adjusted EBITDA	29.4	24.1
TwinSpires | Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	29.4	24.1
Gaming
Segment Reporting Information [Line Items]
Adjusted EBITDA	129.5	91.1
Gaming | Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	129.5	91.1
Rivers Des Plaines
Segment Reporting Information [Line Items]
Rivers Des Plaines' legal reserves and transaction costs	$ 0.0	$ 0.3