Discontinued Operations and Assets Held for Sale - Income (Loss) From Discontinued Operations (Details) $ / a in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Nov. 22, 2021 USD ($) a $ / a	Sep. 29, 2021 USD ($) a
Big Fish Games | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenue	$ 0.0	$ 0.0	$ 0.0
Operating expenses	0.0	0.0	0.0
Selling, general and administrative expense	0.0	0.1	3.5
Research and development	0.0	0.0	0.0
Legal settlement	0.0	124.0	0.0
Total operating expense	0.0	124.1	3.5
Operating loss	0.0	(124.1)	(3.5)
Loss from discontinued operations before provision for income taxes	0.0	(124.1)	(3.5)
Income tax benefit	0.0	28.7	1.1
Loss from discontinued operations, net of tax	0.0	$ (95.4)	$ (2.4)
Arlington Park | Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of land sold | a					326
Aggregate consideration					$ 197.2
Arlington International Racecourse | Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset held for sale	81.5
Severance costs	1.4
Multi-employer pension liability	3.9
Calder Property | Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of land sold | a				115.7
Aggregate consideration				$ 291.0
Asset held for sale	$ 6.3
Sale agreement, per acre | $ / a				2.5