Significant Accounting Policies - Revenue Disaggregation and Customer-Related Liabilities (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($) agreement	Dec. 31, 2019 USD ($)
Online sports betting and iGaming market access
Disaggregation of Revenue [Line Items]
Customer-related liabilities	$ 51.8	$ 43.6
Number of operator agreements containing ordinary shares and warrants | agreement	2
Loyalty credit obligation
Disaggregation of Revenue [Line Items]
Customer-related liabilities	$ 35.2	36.2
Customer-related liabilities, term	6 months
Advance payments on goods and services yet to be provided and unpaid wagers
Disaggregation of Revenue [Line Items]
Customer-related liabilities	$ 42.1	42.2
Customer-related liabilities, long-term	$ 0.6	$ 0.6