Segment Information Adjusted EBITDA by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 279.5	$ 288.4
Research & development	(10.3)	(10.8)
Adjusted EBITDA	57.3	46.7
Racing Segment [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	26.1	28.5
Taxes & purses	(10.2)	(11.2)
Platform & development fees	0.0	0.0
Marketing & advertising	(0.7)	(0.8)
Salaries & benefits	(8.6)	(8.4)
Content expense	(3.2)	(3.3)
SG&A expense	(3.8)	(3.9)
Research & development	0.0	0.0
Other operating expense	9.3	8.4
Other income (expense)	0.0	0.1
Adjusted EBITDA	(9.7)	(7.4)
Casino Segment [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	87.5	86.5
Taxes & purses	(29.1)	(28.4)
Platform & development fees	0.0	0.0
Marketing & advertising	(3.0)	(3.4)
Salaries & benefits	(13.1)	(12.1)
Content expense	0.0	0.0
SG&A expense	(5.2)	(5.1)
Research & development	0.0	0.0
Other operating expense	11.4	9.7
Other income (expense)	9.6	6.5
Adjusted EBITDA	35.3	34.3
TwinSpires [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	52.3	49.9
Taxes & purses	(3.0)	(2.8)
Platform & development fees	0.0	0.0
Marketing & advertising	(1.0)	(1.0)
Salaries & benefits	(2.2)	(2.3)
Content expense	(25.4)	(23.9)
SG&A expense	(2.7)	(2.8)
Research & development	0.0	0.0
Other operating expense	4.8	5.0
Other income (expense)	0.0	0.0
Adjusted EBITDA	13.2	12.1
Big Fish Games [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	112.0	122.1
Taxes & purses	0.0	0.0
Platform & development fees	(41.5)	(44.1)
Marketing & advertising	(24.5)	(42.8)
Salaries & benefits	(7.0)	(6.1)
Content expense	0.0	0.0
SG&A expense	(4.7)	(4.9)
Research & development	(10.3)	(10.8)
Other operating expense	3.7	3.9
Other income (expense)	0.0	(0.6)
Adjusted EBITDA	20.3	8.9
Other Segments [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	5.5	4.9
Taxes & purses	0.0	0.0
Platform & development fees	0.0	0.0
Marketing & advertising	0.0	0.0
Salaries & benefits	(2.9)	(2.7)
Content expense	0.0	0.0
SG&A expense	(0.8)	(0.7)
Research & development	0.0	0.0
Other operating expense	1.3	0.7
Other income (expense)	0.1	0.0
Adjusted EBITDA	0.6	0.8
Corporate
Segment Reporting Information [Line Items]
Net revenue from external customers	0.0	0.0
Taxes & purses	0.0	0.0
Platform & development fees	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	(2.2)	(1.8)
Research & development	0.0	0.0
Other operating expense	0.2	0.3
Other income (expense)	0.0	0.1
Adjusted EBITDA	$ (2.4)	$ (2.0)