Goodwill and Intangible Assets (Schedule of Goodwill) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Goodwill [Roll Forward]
Balance at December 31, 2019	$ 239
Goodwill Impairment	(167)	$ (167)	$ (229)
Balance at March 31, 2020	72	239
Western Hemisphere
Goodwill [Roll Forward]
Balance at December 31, 2019	0
Goodwill Impairment	0
Balance at March 31, 2020		0
Eastern Hemisphere
Goodwill [Roll Forward]
Balance at December 31, 2019	239
Goodwill Impairment	(167)
Balance at March 31, 2020	$ 72	$ 239