Segment Information - Information About Reported Segments (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($) Segments	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Racing	$ 165,300,000	$ 156,100,000	$ 189,200,000	$ 182,300,000
Casinos	88,300,000	84,400,000	175,800,000	170,900,000
TwinSpires	80,500,000	68,400,000	132,500,000	118,000,000
Big Fish Games	112,600,000	125,200,000	224,600,000	247,300,000
Other Investments	$ 5,200,000	4,400,000	9,300,000	8,400,000
Number of Operating Segments | Segments	6
Property, Plant and Equipment, Additions			64,000,000	34,500,000
Intercompany net revenues	$ 0	0	0	0
Adjusted EBITDA	173,000,000	160,200,000	230,300,000	206,900,000
Stock-based compensation	6,700,000	5,300,000	11,700,000	9,400,000
Other income, expense:	0	(300,000)	(100,000)	(300,000)
Interest, depreciation and amortization expense related to equity investments	3,100,000	2,500,000	6,600,000	5,000,000
Other charges and recoveries, net	0	0	0	400,000
Acquisition expense, net	800,000	1,100,000	1,000,000	3,800,000
Calder exit costs	200,000	1,500,000	600,000	1,900,000
Total adjustments to EBITDA	(10,800,000)	(10,700,000)	(20,000,000)	(20,800,000)
Adjusted Earnings Before Interest, Tax, Depreciation, and Amortization	173,000,000	160,200,000	230,300,000	206,900,000
Total adjustments to EBITDA	24,800,000	26,900,000	49,300,000	53,900,000
Adjusted EBITDA	11,600,000	11,100,000	23,400,000	21,700,000
Income (loss) from operations before provision for income taxes	125,800,000	111,500,000	137,600,000	110,500,000
Income tax (provision) benefit	47,500,000	41,700,000	52,000,000	37,900,000
Earnings Before Interest Taxes Depreciation and Amortization	162,200,000	149,500,000	210,300,000	186,100,000
Net income	78,300,000	69,800,000	85,600,000	72,600,000
Foreign currency translation, net of tax	300,000	(200,000)	400,000	(200,000)
Comprehensive income	78,000,000	70,000,000	85,200,000	72,800,000
Racing Segment [Member]
Segment Reporting Information [Line Items]
Racing	165,300,000	156,100,000	189,200,000	182,300,000
Property, Plant and Equipment, Additions			38,400,000	20,700,000
Intercompany net revenues	10,400,000	8,600,000	12,600,000	10,900,000
Adjusted EBITDA	98,700,000	91,300,000	89,000,000	83,900,000
Racing Segment [Member] | Churchill Downs
Segment Reporting Information [Line Items]
Racing	136,700,000	129,100,000	139,000,000	131,400,000
Intercompany net revenues	8,400,000	7,000,000	8,700,000	7,300,000
Racing Segment [Member] | Arlington Park
Segment Reporting Information [Line Items]
Racing	18,000,000	16,800,000	26,500,000	25,800,000
Intercompany net revenues	1,900,000	1,600,000	2,900,000	2,600,000
Racing Segment [Member] | Fair Grounds
Segment Reporting Information [Line Items]
Racing	10,000,000	9,500,000	22,500,000	23,800,000
Intercompany net revenues	100,000	0	1,000,000	1,000,000
Racing Segment [Member] | Calder
Segment Reporting Information [Line Items]
Racing	600,000	700,000	1,200,000	1,300,000
Casino Segment [Member]
Segment Reporting Information [Line Items]
Casinos	88,300,000	84,400,000	175,800,000	170,900,000
Property, Plant and Equipment, Additions			15,600,000	6,800,000
Adjusted EBITDA	37,500,000	33,300,000	72,800,000	67,600,000
Casino Segment [Member] | Oxford Casino
Segment Reporting Information [Line Items]
Casinos	23,100,000	21,100,000	44,000,000	41,000,000
Casino Segment [Member] | Riverwalk Casino
Segment Reporting Information [Line Items]
Casinos	12,000,000	12,400,000	23,500,000	25,100,000
Casino Segment [Member] | Harlows Casino
Segment Reporting Information [Line Items]
Casinos	12,500,000	11,900,000	26,000,000	24,900,000
Casino Segment [Member] | Calder Casinos
Segment Reporting Information [Line Items]
Casinos	21,800,000	20,500,000	43,200,000	40,800,000
Casino Segment [Member] | Fair Grounds Slots
Segment Reporting Information [Line Items]
Casinos	8,800,000	8,800,000	19,000,000	19,400,000
Casino Segment [Member] | VSI
Segment Reporting Information [Line Items]
Casinos	9,800,000	9,500,000	19,500,000	19,300,000
Casino Segment [Member] | Saratoga Casino Holdings, LLC [Member]
Segment Reporting Information [Line Items]
Casinos	300,000	200,000	600,000	400,000
TwinSpires [Member]
Segment Reporting Information [Line Items]
TwinSpires	80,500,000	68,400,000	132,500,000	118,000,000
Property, Plant and Equipment, Additions			5,200,000	3,700,000
Intercompany net revenues	300,000	300,000	600,000	600,000
Adjusted EBITDA	19,300,000	18,800,000	32,500,000	30,900,000
Big Fish Games [Member]
Segment Reporting Information [Line Items]
Big Fish Games	112,600,000	125,200,000	224,600,000	247,300,000
Property, Plant and Equipment, Additions			3,500,000	2,200,000
Adjusted EBITDA	18,300,000	17,800,000	38,600,000	26,700,000
Other Investments Segment [Member]
Segment Reporting Information [Line Items]
Other Investments	5,200,000	4,400,000	9,300,000	8,400,000
Property, Plant and Equipment, Additions			700,000	500,000
Intercompany net revenues	1,300,000	1,400,000	2,700,000	2,300,000
Corporate
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Additions			600,000	600,000
Adjusted EBITDA	(2,100,000)	(2,300,000)	(4,500,000)	(4,300,000)
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intercompany net revenues	(12,000,000)	(10,300,000)	(15,900,000)	(13,800,000)
Social casino | Big Fish Games [Member]
Segment Reporting Information [Line Items]
Big Fish Games	49,500,000	46,500,000	95,700,000	94,000,000
Casual and mid-core free-to-play | Big Fish Games [Member]
Segment Reporting Information [Line Items]
Big Fish Games	43,900,000	56,000,000	89,200,000	106,400,000
Premium | Big Fish Games [Member]
Segment Reporting Information [Line Items]
Big Fish Games	19,200,000	22,700,000	39,700,000	46,900,000
Saratoga Harness Racing Inc Joint Venture [Member]
Segment Reporting Information [Line Items]
Adjusted Corporate EBITDA	(2,100,000.0)	(2,300,000.0)	(4,500,000.0)	(4,300,000.0)
Saratoga Harness Racing Inc Joint Venture [Member] | Racing Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	98,700,000.0	91,300,000.0	89,000,000	83,900,000.0
Saratoga Harness Racing Inc Joint Venture [Member] | Casino Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	37,500,000.0	33,300,000.0	72,800,000.0	67,600,000.0
Saratoga Harness Racing Inc Joint Venture [Member] | TwinSpires [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	19,300,000.0	18,800,000.0	32,500,000.0	30,900,000.0
Saratoga Harness Racing Inc Joint Venture [Member] | Big Fish Games [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	18,300,000.0	17,800,000.0	38,600,000.0	26,700,000.0
Saratoga Harness Racing Inc Joint Venture [Member] | Other Investments Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 1,300,000.0	$ 1,300,000.0	$ 1,900,000.0	$ 2,100,000.0