Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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-Name Accounting Standards Codification
-Topic 350
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-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill	$ 366.8		$ 366.8
Revision of Prior Period, Adjustment \| TwinSpires
Goodwill [Line Items]
Goodwill		$ 4.0
Revision of Prior Period, Adjustment \| Gaming
Goodwill [Line Items]
Goodwill		$ (4.0)