Condensed Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net revenue:
Racing	$ 23.7	$ 23.9
TwinSpires	63.2	52.0
Casino	98.1	87.5
Other Investments	4.3	4.1
Total net revenue	189.3	167.5
Operating expense:
Racing	35.9	36.4
TwinSpires	44.0	36.4
Casino	64.8	62.7
Other Investments	4.6	3.9
Corporate	0.5	0.6
Selling, general and administrative expense	18.4	18.6
Calder exit costs	0.0	0.4
Transaction expense, net	1.4	0.0
Total operating expense	169.6	159.0
Operating income	19.7	8.5
Other income (expense):
Interest expense, net	(9.6)	(11.8)
Equity in income of unconsolidated investments	6.5	6.1
Miscellaneous, net	0.1	0.0
Total other expense	(3.0)	(5.7)
Income (loss) from operations before provision for income taxes	16.7	2.8
Income tax provision	(2.6)	(0.6)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	14.1	2.2
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	167.9	5.1
Net income	$ 182.0	$ 7.3
Net earnings per common share data:
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.98	$ 0.13
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	11.63	0.31
Diluted	12.61	0.44
Income (Loss) from Continuing Operations, Per Diluted Share	0.97	0.13
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share	11.58	0.31
Earnings Per Share, Diluted [Abstract]
Diluted	$ 12.55	$ 0.44
Weighted average shares outstanding:
Numerator for diluted net income per common share:	14.4	16.3
Diluted (in shares)	14.5	16.8
Other comprehensive income (loss):
Foreign currency translation, net of tax	$ 0.0	$ (0.1)
Other comprehensive income (loss)	0.0	(0.1)
Comprehensive income	$ 182.0	$ 7.2