Segment Information Adjusted EBITDA by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 438.5	$ 409.2	$ 726.9	$ 660.1
Research & development	(9.7)	(9.9)	(20.5)	(20.1)
Total segment Adjusted EBITDA	162.9	158.9	215.7	208.7
Racing Segment [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	164.7	162.2	193.2	188.1
Taxes & purses	(30.3)	(31.6)	(41.5)	(41.1)
Platform & development fees	0.0	0.0	0.0	0.0
Marketing & advertising	(1.9)	(3.5)	(2.7)	(4.3)
Salaries & benefits	(12.7)	(12.4)	(21.1)	(20.8)
Content expense	(4.8)	(4.5)	(8.1)	(7.7)
SG&A expenses	(4.0)	(5.6)	(7.9)	(8.7)
Research & development	0.0	0.0	0.0	0.0
Other operating expense	(19.9)	(19.6)	(28.3)	(29.8)
Other income (expenses)	0.2	0.2	0.3	0.3
Total segment Adjusted EBITDA	91.3	85.2	83.9	76.0
Casino Segment [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	84.4	83.8	170.9	169.8
Taxes & purses	(28.0)	(27.9)	(56.5)	(55.9)
Platform & development fees	0.0	0.0	0.0	0.0
Marketing & advertising	(3.1)	(3.1)	(6.5)	(6.2)
Salaries & benefits	(12.7)	(12.8)	(24.8)	(25.4)
Content expense	0.0	0.0	0.0	0.0
SG&A expenses	(5.4)	(4.8)	(10.4)	(11.0)
Research & development	0.0	0.0	0.0	0.0
Other operating expense	(9.7)	(10.6)	(19.4)	(21.3)
Other income (expenses)	7.8	4.9	14.3	9.9
Total segment Adjusted EBITDA	33.3	29.5	67.6	59.9
TwinSpires [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	68.5	61.0	118.2	106.6
Taxes & purses	(2.0)	(2.7)	(4.8)	(4.6)
Platform & development fees	0.0	0.0	0.0	0.0
Marketing & advertising	(3.3)	(2.1)	(4.2)	(3.0)
Salaries & benefits	(2.3)	(2.4)	(4.6)	(4.9)
Content expense	(33.5)	(29.7)	(57.4)	(52.3)
SG&A expenses	(2.8)	(2.6)	(5.6)	(5.5)
Research & development	0.0	0.0	0.0	0.0
Other operating expense	(6.2)	(5.4)	(11.1)	(9.9)
Other income (expenses)	0.0	0.0	0.0	(0.2)
Total segment Adjusted EBITDA	18.4	16.1	30.5	26.2
Big Fish Games [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	125.2	104.5	247.3	196.4
Taxes & purses	0.0	0.0	0.0	0.0
Platform & development fees	(45.9)	(35.6)	(90.0)	(66.9)
Marketing & advertising	(37.1)	(25.6)	(79.9)	(54.8)
Salaries & benefits	(6.2)	(5.8)	(12.2)	(11.1)
Content expense	0.0	0.0	0.0	0.0
SG&A expenses	(4.3)	(3.6)	(9.2)	(8.8)
Research & development	(9.7)	(9.9)	(20.5)	(20.1)
Other operating expense	(3.8)	(3.6)	(7.9)	(7.0)
Other income (expenses)	(0.4)	(0.3)	(0.9)	(0.5)
Change in deferred revenue(1)	2.7	8.2	8.8	21.1
Total segment Adjusted EBITDA	20.5	28.3	35.5	48.3
Other Segments [Member]
Segment Reporting Information [Line Items]
Net revenue from external customers	5.8	5.6	10.7	10.0
Taxes & purses	0.0	0.0	0.0	0.0
Platform & development fees	0.0	0.0	0.0	0.0
Marketing & advertising	0.0	0.0	0.0	0.0
Salaries & benefits	(2.8)	(2.8)	(5.5)	(5.5)
Content expense	0.0	0.0	0.0	0.0
SG&A expenses	(0.9)	(0.7)	(1.6)	(1.1)
Research & development	0.0	0.0	0.0	0.0
Other operating expense	(1.0)	(0.7)	(1.7)	(1.6)
Other income (expenses)	0.2	0.1	0.2	0.1
Total segment Adjusted EBITDA	1.3	1.5	2.1	1.9
Corporate
Segment Reporting Information [Line Items]
Net revenue from external customers	0.2	0.3	0.4	0.5
Taxes & purses	0.0	0.0	0.0	0.0
Platform & development fees	0.0	0.0	0.0	0.0
Marketing & advertising	0.0	0.0	0.0	0.0
Salaries & benefits	0.0	0.0	0.0	0.0
Content expense	0.0	0.0	0.0	0.0
SG&A expenses	(2.0)	(1.6)	(4.0)	(2.8)
Research & development	0.0	0.0	0.0	0.0
Other operating expense	(0.1)	(0.5)	(0.3)	(1.3)
Other income (expenses)	0.0	0.1	0.0	0.0
Total segment Adjusted EBITDA	$ (1.9)	$ (1.7)	$ (3.9)	$ (3.6)