Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Valuation allowance
Goodwill, Impairment Loss	$ 54	$ 0	$ 0
Tax Cuts and Jobs Act of 2017, Change in tax rate, deferred tax asset, income tax expense (benefit)		$ 36
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	$ 7
Effective Income Tax Rate Reconciliation, Goodwill Impairment, Percent	(2.20%)	0.00%	0.00%
SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member]
Valuation allowance
Additions	$ 119		$ 86
UK Gaming [Member]
Valuation allowance
Goodwill, Impairment Loss	$ 54