Discontinued Operations - Additional Information (Details) - Big Fish Games - USD ($) $ in Millions		9 Months Ended
	May 22, 2020	Sep. 30, 2020	Jan. 09, 2018
Pro Forma | Cheryl Kater v. Churchill Downs Incorporated | Pending Litigation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amount to be paid into a settlement fund	$ 155.0
CDI | Cheryl Kater v. Churchill Downs Incorporated | Pending Litigation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax settlement paid in cash	124.0	$ 124.0
Aristocrat | Cheryl Kater v. Churchill Downs Incorporated | Pending Litigation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax settlement paid in cash	$ 31.0
Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Purchase price			$ 990.0