Debt and Other Obligations (Components of Interest Expense and Amortization of Deferred Financing Costs) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt and Other Obligations [Abstract]
Interest Expense, Debt, Excluding Amortization	$ 173	$ 158	$ 509	$ 473
Amortization of deferred financing costs and adjustments on long-term debt	5	5	15	16
Other, net of capitalized interest	(5)	(3)	(14)	(11)
Interest expense and amortization of deferred financing costs	$ 173	$ 160	$ 510	$ 478