Segment Information - Schedule of Total Assets and Capital Expenditures by Operating Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 2,686.4	$ 2,551.0
Capital expenditures	234.2	131.2	$ 149.4
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,584.2	1,641.9
Capital expenditures	56.3	78.2	140.0
All Other
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,102.2	909.1
Capital expenditures	177.9	53.0	9.4
Churchill Downs | Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	377.7	370.3
Capital expenditures	38.2	31.4	109.6
Online Wagering | Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	249.1	241.5
Capital expenditures	11.6	9.7	9.7
Gaming
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	957.4	1,030.1
Gaming | Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Capital expenditures	$ 6.5	$ 37.1	$ 20.7