Reportable Segments (Reconciliation of Reportable Segment Net Income to Consolidated Net Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net financing costs	$ (26)	$ (29)	$ (52)	$ (58)
Stock-based compensation expense	(11)	(14)	(25)	(23)
Exploratory research	(23)	(28)	(47)	(55)
Corporate contributions	(6)	(16)	(22)	(23)
Gain on realignment of equity investment		2,676		2,676
Equity in earnings of affiliated companies, net of impairments	31	48	110	104
Unrealized loss on translated earnings contracts	148	(1,253)	(370)	(2,203)
Resolution of Department of Justice investigation		(98)		(98)
Income tax benefit	15	653	233	1,054
Other corporate items	(45)	(50)	(32)	(66)
Net income	439	2,207	525	1,839
Reportable Segments [Member]
Net income	414	373	841	671
Non Reportable Segments [Member]
Net income	$ (58)	$ (55)	$ (111)	$ (140)