Segment Information - Reconciliation of Comprehensive Income to Adjusted EBITDA by Segment (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
Segment Reporting Information [Line Items]
Net income attributable to Churchill Downs Incorporated	$ 65.4	$ 209.3	$ 80.4	$ 61.0	$ 143.0	$ 155.7	$ 355.1	$ 359.7
Net income attributable to noncontrolling interest	0.8			0.0			1.7	0.0
Net income and comprehensive income	66.2			61.0			356.8	359.7
Depreciation and amortization	49.6			42.1			145.7	121.8
Interest expense	73.1			67.9			217.0	197.8
Income tax provision	19.9			20.8			125.4	130.2
EBITDA	208.8			191.8			844.9	809.5
Stock-based compensation expense	7.1			8.1			23.2	24.8
Pre-opening expense	7.8			5.0			23.6	11.4
Arlington exit costs	0.0			0.1			0.0	9.4
Other expenses, net	1.0			0.7			1.3	7.6
Asset impairments	3.9			0.0			3.9	24.5
Transaction expense, net	(4.0)			1.5			0.7	1.8
Interest, depreciation and amortization expense related to equity investments	10.6			10.1			31.4	29.8
Other charges and recoveries, net	0.1			0.9			(6.7)	0.0
Gain on sale of Arlington	0.0			0.0			0.0	(114.0)
Total adjustments to EBITDA	26.5			26.4			77.7	(4.7)
Adjusted EBITDA	235.3			218.2			922.6	804.8
Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	258.8			237.1			988.1	858.9
All Other
Segment Reporting Information [Line Items]
Adjusted EBITDA	(23.5)			(18.9)			(65.5)	(54.1)
Live and Historical Racing | Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	93.0			80.9			473.0	386.5
TwinSpires | Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	42.5			33.9			128.3	97.2
Gaming | Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	123.3			122.3			386.8	375.2
Rivers Des Plaines
Segment Reporting Information [Line Items]
Rivers Des Plaines' legal reserves and transaction costs	$ 0.0			$ 0.0			$ 0.3	$ 0.0