Segment Information Adjusted EBITDA by Segment (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Net revenue	$ 379,400,000	$ 339,300,000	$ 568,700,000	$ 506,800,000
Adjusted EBITDA	174,500,000	154,000,000	223,700,000	190,300,000
Racing Segment [Member]
Segment Reporting Information [Line Items]
Net revenue	194,100,000	175,700,000	220,300,000	201,800,000
Taxes & purses	34,400,000	32,900,000	44,700,000	43,100,000
Marketing & advertising	3,600,000	2,200,000	4,400,000	2,900,000
Salaries & benefits	15,300,000	13,500,000	23,900,000	22,100,000
Content expense	4,700,000	4,700,000	7,800,000	7,900,000
SG&A expense	4,600,000	4,200,000	8,600,000	8,000,000
Other operating expense	22,800,000	20,000,000	31,600,000	29,300,000
Other income	400,000	500,000	400,000	500,000
Adjusted EBITDA	109,100,000	98,700,000	99,700,000	89,000,000
Casino Segment [Member]
Segment Reporting Information [Line Items]
Net revenue	98,200,000	88,300,000	196,300,000	175,800,000
Taxes & purses	33,400,000	29,700,000	65,800,000	58,800,000
Marketing & advertising	3,500,000	3,000,000	6,700,000	6,000,000
Salaries & benefits	13,600,000	13,400,000	27,100,000	26,500,000
Content expense	0	0	0	0
SG&A expense	5,600,000	5,600,000	11,000,000	10,800,000
Other operating expense	11,100,000	9,800,000	21,200,000	21,200,000
Other income	12,900,000	10,700,000	23,700,000	20,300,000
Adjusted EBITDA	43,900,000	37,500,000	88,200,000	72,800,000
TwinSpires [Member]
Segment Reporting Information [Line Items]
Net revenue	94,100,000	80,800,000	157,700,000	133,100,000
Taxes & purses	4,600,000	4,100,000	8,000,000	7,100,000
Marketing & advertising	3,100,000	4,600,000	3,900,000	5,600,000
Salaries & benefits	2,400,000	2,600,000	4,500,000	4,800,000
Content expense	49,800,000	40,200,000	82,000,000	65,600,000
SG&A expense	2,900,000	3,000,000	5,700,000	5,700,000
Other operating expense	8,200,000	7,000,000	14,000,000	11,800,000
Other income	0	0	0	0
Adjusted EBITDA	23,100,000	19,300,000	39,600,000	32,500,000
Other Segments [Member]
Segment Reporting Information [Line Items]
Net revenue	6,500,000	6,500,000	12,000,000	12,000,000
Taxes & purses	0	0	0	0
Marketing & advertising	100,000	0	100,000	0
Salaries & benefits	3,600,000	3,300,000	6,800,000	6,200,000
Content expense	0	0	0	0
SG&A expense	700,000	700,000	1,400,000	1,500,000
Other operating expense	1,100,000	1,200,000	2,400,000	2,500,000
Other income	100,000	0	100,000	100,000
Adjusted EBITDA	1,100,000	1,300,000	1,400,000	1,900,000
Corporate
Segment Reporting Information [Line Items]
Net revenue	0	0	0	0
Taxes & purses	0	0	0	0
Marketing & advertising	0	0	0	0
Salaries & benefits	0	0	0	0
Content expense	0	0	0	0
SG&A expense	2,600,000	2,500,000	5,000,000	5,400,000
Other operating expense	100,000	300,000	300,000	500,000
Other income	0	0	100,000	0
Adjusted EBITDA	(2,700,000)	(2,800,000)	(5,200,000)	(5,900,000)
Saratoga Harness Racing Inc Joint Venture [Member] | Racing Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	109,100,000.0	98,700,000.0	99,700,000.0	89,000,000
Saratoga Harness Racing Inc Joint Venture [Member] | Casino Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	43,900,000.0	37,500,000.0	88,200,000.0	72,800,000.0
Saratoga Harness Racing Inc Joint Venture [Member] | TwinSpires [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	23,100,000.0	19,300,000.0	39,600,000.0	32,500,000.0
Saratoga Harness Racing Inc Joint Venture [Member] | Other Investments Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 1,100,000.0	$ 1,300,000.0	$ 1,400,000.0	$ 1,900,000.0