Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net revenue:
Racing	$ 257.3	$ 251.1	$ 248.0
Casino	350.5	332.8	332.9
TwinSpires	255.6	221.6	201.1
Other Investments	19.2	16.9	16.6
Total net revenue	882.6	822.4	798.6
Operating expense:
Racing	192.5	187.7	189.9
Casino	247.3	241.3	241.1
TwinSpires	170.2	146.7	135.4
Other Investments	17.8	16.5	16.3
Corporate	2.0	1.8	0.1
Selling, general and administrative expense	83.1	79.4	75.6
Impairment of tangible and other intangible assets	21.7	0.0	0.0
Gain on Calder land sale	0.0	(23.7)	0.0
Calder exit costs	0.8	2.5	13.9
Other, net	1.5	(2.3)	0.0
Total operating expense	736.9	649.9	672.3
Operating income	145.7	172.5	126.3
Other income (expense):
Interest expense	(49.3)	(43.7)	(28.6)
Loss on extinguishment of debt	(20.7)	0.0	0.0
Equity in income of unconsolidated investments	25.5	17.4	11.2
Miscellaneous, net	1.3	1.2	6.5
Total other expense	(43.2)	(25.1)	(10.9)
Income from continuing operations before provision for income taxes	102.5	147.4	115.4
Income tax benefit (provision)	19.9	(50.7)	(44.6)
Income from continuing operations, net of tax	122.4	96.7	70.8
Income (loss) from discontinued operations, net of tax	18.1	11.4	(5.6)
Net income	$ 140.5	$ 108.1	$ 65.2
Net income (loss) per common share data - basic:
Continuing operations (in dollars per share)	$ 7.76	$ 5.83	$ 4.08
Discontinued operations (in dollars per share)	1.15	0.69	(0.33)
Net income per common share - basic (in dollars per share)	8.91	6.52	3.75
Net income (loss) per common share data - diluted:
Continuing operations (in dollars per share)	7.64	5.74	4.03
Discontinued operations (in dollars per share)	1.13	0.68	(0.32)
Net income per common share - diluted (in dollars per share)	$ 8.77	$ 6.42	$ 3.71
Weighted average shares outstanding:
Basic (in shares)	15.7	16.4	17.2
Diluted (in shares)	16.0	16.8	17.6
Other comprehensive loss:
Foreign currency translation, net of tax	$ (0.1)	$ 0.2	$ (0.5)
Change in pension benefits, net of tax	0.0	(0.8)	0.0
Other comprehensive loss	(0.1)	(0.6)	(0.5)
Comprehensive income	$ 140.4	$ 107.5	$ 64.7