Segment Information - Information About Reported Segments (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) Segments	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Gain on Ocean Downs/Saratoga transaction	$ (54,900,000)	$ 0	$ (54,900,000)	$ 0
Racing	37,600,000	38,800,000	243,800,000	228,000,000
TwinSpires	71,800,000	65,900,000	228,700,000	198,400,000
Casino	105,000,000	87,500,000	301,300,000	263,300,000
Other Investments	6,900,000	4,700,000	16,200,000	14,000,000
Adjusted EBITDA	$ 62,100,000	58,100,000	285,800,000	248,400,000
Number of Operating Segments | Segments	5
Property, Plant and Equipment, Additions			125,500,000	89,100,000
Intercompany net revenues	$ 0	0	0	0
Comprehensive income	56,900,000	17,300,000	341,800,000	102,500,000
Foreign currency translation, net of tax	(400,000)	(500,000)	(400,000)	(100,000)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Noncontrolling Interest	200,000	100,000	0	100,000
Net income	56,300,000	16,700,000	341,400,000	102,300,000
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	1,700,000	(3,600,000)	(166,100,000)	(14,300,000)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	58,000,000	13,100,000	175,300,000	88,000,000
Depreciation and amortization	16,700,000	13,400,000	45,800,000	73,300,000
Interest expense	9,900,000	12,600,000	29,200,000	36,000,000
Income tax (provision) benefit	16,700,000	10,300,000	52,100,000	57,900,000
Earnings Before Interest Taxes Depreciation and Amortization	101,300,000	49,400,000
Stock-based compensation	3,900,000	3,900,000	16,500,000	17,500,000
Pre-Opening Costs	2,600,000	0
Other income, expense:	(200,000)	0
Interest, depreciation and amortization expense related to equity investments	3,600,000	4,000,000
Acquisition expenses, net	5,400,000	600,000	0	1,700,000
Calder exit costs	0	200,000	0	800,000
Total adjustments to EBITDA	(39,200,000)	8,700,000	(16,600,000)	24,500,000
Adjusted EBITDA	62,100,000	58,100,000	285,800,000	248,400,000
Racing Segment [Member]
Segment Reporting Information [Line Items]
Racing	37,600,000	38,800,000	243,800,000	228,000,000
Adjusted EBITDA	(1,200,000)	1,700,000	98,500,000	90,700,000
Property, Plant and Equipment, Additions			53,600,000	47,800,000
Intercompany net revenues	3,400,000	3,100,000	17,500,000	15,700,000
Racing Segment [Member] | Churchill Downs
Segment Reporting Information [Line Items]
Racing	8,500,000	8,100,000	165,400,000	147,100,000
Intercompany net revenues	1,000,000	900,000	10,700,000	9,600,000
Racing Segment [Member] | Arlington Park
Segment Reporting Information [Line Items]
Racing	23,700,000	25,000,000	49,700,000	51,500,000
Intercompany net revenues	2,300,000	2,200,000	5,600,000	5,100,000
Racing Segment [Member] | Fair Grounds
Segment Reporting Information [Line Items]
Racing	4,800,000	5,000,000	26,800,000	27,500,000
Intercompany net revenues	0	0	1,100,000	1,000,000
Racing Segment [Member] | Calder
Segment Reporting Information [Line Items]
Racing	600,000	700,000	1,900,000	1,900,000
Intercompany net revenues	100,000	0	100,000	0
Casino Segment [Member]
Segment Reporting Information [Line Items]
Casino	105,000,000	87,500,000	301,300,000	263,300,000
Adjusted EBITDA	45,700,000	39,500,000	133,900,000	112,300,000
Property, Plant and Equipment, Additions			9,200,000	26,000,000
Casino Segment [Member] | Oxford Casino
Segment Reporting Information [Line Items]
Casino	28,900,000	25,200,000	79,300,000	69,200,000
Casino Segment [Member] | Riverwalk Casino
Segment Reporting Information [Line Items]
Casino	12,800,000	12,200,000	40,800,000	35,700,000
Casino Segment [Member] | Harlows Casino
Segment Reporting Information [Line Items]
Casino	12,100,000	12,300,000	37,900,000	38,300,000
Casino Segment [Member] | Calder Casinos
Segment Reporting Information [Line Items]
Casino	23,400,000	19,400,000	73,000,000	62,600,000
Casino Segment [Member] | Fair Grounds Slots
Segment Reporting Information [Line Items]
Casino	9,100,000	8,700,000	28,900,000	27,700,000
Casino Segment [Member] | Ocean Downs LLC and Racing Services LLC [Member]
Segment Reporting Information [Line Items]
Casino	8,100,000	0	8,100,000	0
Casino Segment [Member] | VSI
Segment Reporting Information [Line Items]
Casino	10,600,000	9,300,000	32,700,000	28,800,000
Casino Segment [Member] | Saratoga Casino Holdings, LLC [Member]
Segment Reporting Information [Line Items]
Casino	0	400,000	600,000	1,000,000
TwinSpires [Member]
Segment Reporting Information [Line Items]
TwinSpires	71,800,000	65,900,000	228,700,000	198,400,000
Adjusted EBITDA	19,300,000	18,800,000	58,900,000	51,300,000
Property, Plant and Equipment, Additions			7,100,000	7,300,000
Intercompany net revenues	300,000	200,000	1,100,000	800,000
Other Investments Segment [Member]
Segment Reporting Information [Line Items]
Other Investments	6,900,000	4,700,000	16,200,000	14,000,000
Property, Plant and Equipment, Additions			53,800,000	1,300,000
Intercompany net revenues	900,000	1,000,000	3,600,000	3,700,000
Corporate
Segment Reporting Information [Line Items]
Adjusted EBITDA	(2,800,000)	(3,000,000)	(8,000,000)	(8,900,000)
Property, Plant and Equipment, Additions			1,800,000	1,100,000
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intercompany net revenues	(4,600,000)	(4,300,000)	(22,200,000)	(20,200,000)
Saratoga Harness Racing Inc Joint Venture [Member]
Segment Reporting Information [Line Items]
Adjusted Corporate EBITDA	(2,800,000.0)	(3,000,000)	(8,000,000)	(8,900,000.0)
Saratoga Harness Racing Inc Joint Venture [Member] | Racing Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	(1,200,000.0)	1,700,000.0	98,500,000.0	90,700,000.0
Saratoga Harness Racing Inc Joint Venture [Member] | Casino Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	45,700,000.0	39,500,000.0	133,900,000.0	112,300,000.0
Saratoga Harness Racing Inc Joint Venture [Member] | TwinSpires [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	19,300,000.0	18,800,000.0	58,900,000.0	51,300,000.0
Saratoga Harness Racing Inc Joint Venture [Member] | Other Investments Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	1,100,000.0	1,100,000.0	2,500,000.0	3,000,000.0
Continuing Operations [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization			45,800,000	42,000,000
Interest expense			29,200,000	36,000,000
Income tax (provision) benefit			52,100,000	57,900,000
Earnings Before Interest Taxes Depreciation and Amortization			302,400,000	223,900,000
Stock-based compensation	$ 3,900,000	$ 3,900,000	13,100,000	11,700,000
Pre-Opening Costs			3,900,000	300,000
Other income, expense:			(200,000)	0
Interest, depreciation and amortization expense related to equity investments			12,200,000	10,600,000
Acquisition expenses, net			8,900,000	1,100,000
Calder exit costs			$ 0	$ 800,000