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Advanced Sales of Personal Seat Licenses, Contractual Life, Term Two

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Capitalized Computer Software, Useful Life

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The Company recognizes gaming tax expense based on the statutorily required percentage of revenue that is required to be paid to state and local jurisdictions in the states in which wagering occurs. Individual states and local jurisdictions set gaming tax rates.

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The Company recognizes pari-mutuel expense based on the statutorily required percentage of revenue that is required to be paid to state and local jurisdictions in the states in which wagering occurs. Individual states and local jurisdictions set pari-mutuel tax rates.

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Virtual Goods, Average Life

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Amount of expense for amortization of capitalized computer software costs.

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Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Advanced sales of personal seat licenses, contractual life, term one	1 year
Advanced sales of personal seat licenses, contractual life, term two	30 years
Minimum
Variable Interest Entity [Line Items]
Gaming tax rate	1.50%
Pari-Mutuel tax rate	0.50%
Maximum
Variable Interest Entity [Line Items]
Gaming tax rate	46.00%
Pari-Mutuel tax rate	10.00%
Grandstands and buildings \| Minimum
Variable Interest Entity [Line Items]
Property, plant, and equipment, useful life	10 years
Grandstands and buildings \| Maximum
Variable Interest Entity [Line Items]
Property, plant, and equipment, useful life	40 years
Equipment \| Minimum
Variable Interest Entity [Line Items]
Property, plant, and equipment, useful life	2 years
Equipment \| Maximum
Variable Interest Entity [Line Items]
Property, plant, and equipment, useful life	10 years
Furniture and fixtures \| Minimum
Variable Interest Entity [Line Items]
Property, plant, and equipment, useful life	2 years
Furniture and fixtures \| Maximum
Variable Interest Entity [Line Items]
Property, plant, and equipment, useful life	10 years
Tracks and other improvements \| Minimum
Variable Interest Entity [Line Items]
Property, plant, and equipment, useful life	10 years
Tracks and other improvements \| Maximum
Variable Interest Entity [Line Items]
Property, plant, and equipment, useful life	20 years
Game Software Development \| Minimum
Variable Interest Entity [Line Items]
Capitalized computer software useful life	18 months
Game Software Development \| Maximum
Variable Interest Entity [Line Items]
Capitalized computer software useful life	3 years
Enhancements to Game Software Development
Variable Interest Entity [Line Items]
Capitalized computer software useful life	18 months
Internally developed and purchased third party software
Variable Interest Entity [Line Items]
Capitalized computer software developed or acquired for internal use	$ 7.2	$ 6.7	$ 8.9
Capitalized computer software developed or acquired for internal use, amortization expense	$ 6.3	6.0	6.2
Internally developed and purchased third party software \| Maximum
Variable Interest Entity [Line Items]
Property, plant, and equipment, useful life	3 years
TwinSpires
Variable Interest Entity [Line Items]
Percentage earned on total amount wagered	18.30%
Racing
Variable Interest Entity [Line Items]
Percentage earned on total amount wagered	11.10%
Social Casino Games
Variable Interest Entity [Line Items]
Average life of virtual goods	3 days
Other Casual Games
Variable Interest Entity [Line Items]
Average life of virtual goods	4 months
Free-to-play Game Software \| Game Software Development
Variable Interest Entity [Line Items]
Capitalized computer software useful life	18 months
Premium \| Game Software Development
Variable Interest Entity [Line Items]
Capitalized computer software useful life	12 months
Big Fish Games
Variable Interest Entity [Line Items]
Research & development expenditures	$ 39.6	39.0	39.4
Continuing Operations
Variable Interest Entity [Line Items]
Advertising and marketing expense	24.8	23.1	23.0
Discontinued Operations
Variable Interest Entity [Line Items]
Advertising and marketing expense	$ 116.6	$ 127.9	$ 107.7