Investments in and Advances to Unconsolidated Affiliates - Affiliate Income Statement (Details) - USD ($) $ 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
Investments in and Advances to Affiliates [Line Items]
Net revenue	$ 628.5			$ 572.5			$ 2,110.1	$ 1,900.5
Operating and SG&A expense	59.8			50.2			172.0	150.6
Operating income	125.9			112.3			582.2	457.8
Net income attributable to Churchill Downs Incorporated	65.4	$ 209.3	$ 80.4	61.0	$ 143.0	$ 155.7	355.1	359.7
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Investments in and Advances to Affiliates [Line Items]
Net revenue	208.4			208.9			641.2	648.2
Operating and SG&A expense	132.2			135.1			399.3	407.3
Depreciation and amortization	6.8			5.9			20.1	17.5
Total operating expense	139.0			141.0			419.4	424.8
Operating income	69.4			67.9			221.8	223.4
Interest and other, net	(11.1)			(11.1)			(33.5)	(32.7)
Net income attributable to Churchill Downs Incorporated	$ 58.3			$ 56.8			$ 188.3	$ 190.7