Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net Income	$ 4,373	$ 4,526	$ 659
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net change in foreign currency and interest rate derivatives	(43)	(82)	3
Net change in pension and other benefits	(360)	163	(2,194)
Net change in investments	42	(45)	10
Total Other Comprehensive (Loss) Income	(361)	36	(2,181)
Comprehensive Income (Loss)	$ 4,012	$ 4,562	$ (1,522)