Net Income Per Common Share Computations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator for basic and diluted net income per common share:
Net income attributable to Churchill Downs Incorporated	$ 65.4	$ 209.3	$ 80.4	$ 61.0	$ 143.0	$ 155.7	$ 355.1	$ 359.7
Adjustments related to redeemable noncontrolling interest	(1.0)			0.0			(1.8)	0.0
Net income attributable to common shareholders	$ 64.4			$ 61.0			$ 353.3	$ 359.7
Denominator for net income per common share:
Basic (in shares)	73,900			75,200			74,000	75,300
Plus dilutive effect of stock awards (in shares)	700			1,900			600	1,400
Diluted (in shares)	74,600			77,100			74,600	76,700
Basic
Basic net income (in dollars per share)	$ 0.87			$ 0.81			$ 4.78	$ 4.78
Diluted
Diluted net income (in dollars per share)	$ 0.86			$ 0.79			$ 4.73	$ 4.69