Intangible Assets and Goodwill (Schedule of Intangible Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 1,313	$ 1,313
Less: accumulated amortization	(568)	(524)
Intangible assets, net	745	789
Contractual arrangements
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	921	921
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	14	14
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	353	353
Trade names
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	16	16
Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 9	$ 9