Condensed Consolidated Statements Of Comprehensive Earnings - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net revenue:
Racing	$ 26.2	$ 23.8
Casinos	86.5	86.0
TwinSpires	49.4	45.4
Big Fish Games	122.1	91.9
Other Investments	4.0	3.6
Corporate	0.2	0.2
Net revenues	288.4	250.9
Operating expense:
Racing	35.6	36.2
Casinos	61.0	61.1
TwinSpires	34.6	32.6
Big Fish Games	109.4	82.2
Other Investments	3.9	3.8
Corporate	0.6	1.0
Selling, general and administrative expense	23.1	21.5
Research and development	10.8	10.2
Calder exit costs	0.4	0.0
Acquisition-related charges	2.7	6.4
Operating income (loss)	6.3	(4.1)
Other income (expense):
Interest income	0.0	0.2
Interest expense	(10.6)	(7.5)
Equity in income of unconsolidated investments	3.8	3.0
Miscellaneous, net	(0.5)	5.6
Nonoperating Income (Expense)	(7.3)	1.3
Loss from continuing operations before income tax benefit	(1.0)	(2.8)
Income tax benefit	3.8	1.2
Net income (loss)	$ 2.8	$ (1.6)
Earnings Per Share, Basic [Abstract]
Basic	$ 0.17	$ (0.09)
Earnings Per Share, Diluted [Abstract]
Diluted	$ 0.16	$ (0.09)
Weighted average shares outstanding:
Basic	16.5	17.3
Diluted (in shares)	17.0	17.3
Other comprehensive income (loss):
Foreign currency translation, net of tax	$ 0.0	$ (0.3)
Other comprehensive income (loss)	0.0	(0.3)
Comprehensive income (loss)	$ 2.8	$ (1.9)