Significant Accounting Policies - Concentration of Credit Risk and Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts	$ (8.8)	$ (7.7)
Accounts receivable, net	96.4	88.7
Markers issued to customers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, gross	14.8	22.9
Credit card receivables and other advances to customers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, gross	8.9	16.5
Receivables from ATM and cash kiosk transactions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, gross	10.9	14.4
Hotel and banquet receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, gross	2.7	6.5
Racing settlements
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, gross	7.7	6.6
Receivables due from platform providers for social casino games
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, gross	10.5	3.3
Insurance Receivable - Hurricane Laura
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, gross	23.0	0.0
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, gross	$ 26.7	$ 26.2

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