Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 11, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	CHURCHILL DOWNS INC
Entity Central Index Key	0000020212
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Amendment Flag	false
Emerging Growth Company	false
Smaller Reporting Entity	false
Entity Common Stock, Shares Outstanding		40,284,299
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Public Float			$ 3,470,235,704