Condensed Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net revenue:
Racing	$ 23.9	$ 26.2
Casinos	87.5	86.5
TwinSpires	52.0	49.6
Big Fish Games	112.0	122.1
Other Investments	4.1	4.0
Total net revenue	279.5	288.4
Operating expense:
Racing	36.4	35.6
Casinos	62.7	61.0
TwinSpires	36.4	34.6
Big Fish Games	86.9	109.4
Other Investments	3.9	3.9
Corporate	0.7	0.6
Selling, general and administrative expense	24.1	23.1
Research and development	10.3	10.8
Calder exit costs	0.4	0.4
Acquisition expenses, net	0.2	2.7
Total operating expense	262.0	282.1
Operating income	17.5	6.3
Other income (expense):
Interest expense	(11.8)	(10.6)
Equity in income of unconsolidated investments	6.1	3.8
Miscellaneous, net	0.0	(0.5)
Total other expense	(5.7)	(7.3)
Income (loss) from operations before provision for income taxes	11.8	(1.0)
Income tax (provision) benefit	(4.5)	3.8
Net income	$ 7.3	$ 2.8
Earnings Per Share, Basic [Abstract]
Basic	$ 0.44	$ 0.17
Earnings Per Share, Diluted [Abstract]
Diluted	$ 0.44	$ 0.16
Weighted average shares outstanding:
Basic	16.3	16.5
Diluted (in shares)	16.8	17.0
Other comprehensive loss:
Foreign currency translation, net of tax	$ (0.1)	$ 0.0
Other comprehensive loss	(0.1)	0.0
Comprehensive income	$ 7.2	$ 2.8