Summary of Significant Accounting Policies Summary of Significant Accounting Policies - Schedule of Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 87,000,000	$ 250,000,000	$ 737,000,000
Divested			(140,000,000)
Impairments	0	(163,000,000)	(347,000,000)
Goodwill, Ending Balance	87,000,000	87,000,000	250,000,000
United States [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	0	0	384,000,000
Divested			(140,000,000)
Impairments	0	0	(244,000,000)
Goodwill, Ending Balance	0	0	0
Canada [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	0	0	103,000,000
Divested			0
Impairments	0	0	(103,000,000)
Goodwill, Ending Balance	0	0	0
Egypt [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	87,000,000	87,000,000	87,000,000
Divested			0
Impairments	0	0	0
Goodwill, Ending Balance	87,000,000	87,000,000	87,000,000
North Sea [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	0	163,000,000	163,000,000
Divested			0
Impairments	0	(163,000,000)	0
Goodwill, Ending Balance	$ 0	$ 0	$ 163,000,000