Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Reserves and other accrued expenses	$ 89	$ 78
Net operating loss carry forwards	478	296
Tax credit carry forwards	42	40
Interest limitation carryforwards	22	157
Differences in financial reporting and tax basis for:
Other	60	51
Valuation allowance	(328)	(209)
Realizable deferred tax assets	363	413
Differences in financial reporting and tax basis for:
Identifiable intangible assets	(253)	(312)
Property and equipment	(51)	(47)
Other	(14)	(25)
Total deferred tax liabilities	(318)	(384)
Deferred Tax Assets, Net	$ 45	$ 29