Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net revenue:
Net revenue	$ 515.1	$ 185.1	$ 839.4	$ 438.0
Operating expense:
Selling, general and administrative expense	33.4	22.4	63.6	46.5
Asset impairments	11.2	0.0	11.2	17.5
Transaction expense, net	0.0	0.2	0.1	0.5
Total operating expense	379.7	185.5	657.3	450.0
Operating income (loss)	135.4	(0.4)	182.1	(12.0)
Other income (expense):
Interest expense, net	(22.0)	(20.3)	(41.4)	(39.6)
Equity in income (loss) of unconsolidated affiliates	36.4	(11.1)	61.3	(14.4)
Miscellaneous, net	0.1	0.3	0.2	0.3
Total other income (expense)	14.5	(31.1)	20.1	(53.7)
Income (loss) from continuing operations before (provision) benefit for income taxes	149.9	(31.5)	202.2	(65.7)
Income tax (provision) benefit	(41.6)	7.9	(57.8)	19.5
Income (loss) from continuing operations, net of tax	108.3	(23.6)	144.4	(46.2)
Loss from discontinued operations, net of tax	0.0	(95.2)	0.0	(96.1)
Net income (loss)	108.3	(118.8)	144.4	(142.3)
Net loss attributable to noncontrolling interest	0.0	0.0	0.0	(0.1)
Net income (loss) and comprehensive income (loss) attributable to Churchill Downs Incorporated	$ 108.3	$ (118.8)	$ 144.4	$ (142.2)
Net income (loss) per common share data - basic:
Continuing operations (in dollars per share)	$ 2.80	$ (0.59)	$ 3.72	$ (1.16)
Discontinued operations (in dollars per share)	0	(2.41)	0	(2.43)
Net income (loss) per common share data - basic (in dollars per share)	2.80	(3.00)	3.72	(3.59)
Net income (loss) per common share data - diluted:
Continuing operations (in dollars per share)	2.76	(0.59)	3.66	(1.16)
Discontinued operations (in dollars per share)	0	(2.41)	0	(2.43)
Net income (loss) per common share data - diluted (in dollars per share)	$ 2.76	$ (3.00)	$ 3.66	$ (3.59)
Weighted average shares outstanding:
Basic (in shares)	38.7	39.5	38.8	39.6
Diluted (in shares)	39.3	39.5	39.4	39.6
Live and Historical Racing
Net revenue:
Net revenue	$ 175.9	$ 23.3	$ 239.1	$ 51.4
Operating expense:
Operating expense	100.3	33.1	155.0	66.2
TwinSpires
Net revenue:
Net revenue	135.6	121.3	235.3	190.4
Operating expense:
Operating expense	96.8	74.7	169.8	125.5
Gaming
Net revenue:
Net revenue	186.0	37.3	338.0	183.2
Operating expense:
Operating expense	121.0	45.5	227.3	169.6
All Other
Net revenue:
Net revenue	17.6	3.2	27.0	13.0
Operating expense:
Operating expense	$ 17.0	$ 9.6	$ 30.3	$ 24.2