Segment Information - Schedule of Adjusted EBITDA by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total net revenue	$ 1,597.2	$ 1,054.0	$ 1,329.7
Adjusted EBITDA	627.0	286.5	451.4
Live and Historical Racing
Segment Reporting Information [Line Items]
Total net revenue	430.6	188.8	292.2
Taxes and purses	(126.3)	(64.1)	(68.7)
Marketing and advertising	(12.9)	(6.2)	(7.1)
Salaries and benefits	(48.4)	(32.5)	(32.8)
Content expense	(2.5)	(1.5)	(2.6)
Selling, general and administrative expense	(12.8)	(8.7)	(8.3)
Other operating expense	(53.0)	(36.8)	(37.3)
Other income	0.3	0.1	0.2
Adjusted EBITDA	175.0	39.1	135.6
TwinSpires
Segment Reporting Information [Line Items]
Total net revenue	433.1	416.0	296.7
Taxes and purses	(30.6)	(25.1)	(16.2)
Marketing and advertising	(49.4)	(16.5)	(12.3)
Salaries and benefits	(13.9)	(13.0)	(11.4)
Content expense	(206.6)	(202.7)	(152.2)
Selling, general and administrative expense	(9.2)	(8.8)	(7.1)
Other operating expense	(45.4)	(37.1)	(28.2)
Other income	0.0	0.1	0.0
Adjusted EBITDA	78.0	112.9	69.3
Gaming Segment
Segment Reporting Information [Line Items]
Total net revenue	698.4	437.8	689.7
Taxes and purses	(264.4)	(171.6)	(269.4)
Marketing and advertising	(11.8)	(7.5)	(21.4)
Salaries and benefits	(87.1)	(75.9)	(103.3)
Content expense	(4.7)	(3.5)	(5.3)
Selling, general and administrative expense	(27.9)	(25.4)	(29.1)
Other operating expense	(72.3)	(59.7)	(83.6)
Other income	181.7	78.9	100.3
Adjusted EBITDA	$ 411.9	$ 173.1	$ 277.9