Stockholders' Equity Stockholder's Equity (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2017		Jun. 30, 2016		Jun. 30, 2017		Jun. 30, 2016		Dec. 31, 2016		Dec. 31, 2015
Accumulated Other Comprehensive (Loss) Income, Net of Tax	$ (9,065)		$ (10,757)		$ (9,065)		$ (10,757)		$ (9,911)		$ (9,396)
Other comprehensive income (loss), before Reclassifications, Net of Tax					609		(1,645)
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax					237		284
Other Comprehensive Income (Loss), Net of Tax	358		(806)		846		(1,361)
Other Post Employment Benefit Plans [Member]
Accumulated Other Comprehensive (Loss) Income, Net of Tax	(350)		(197)		(350)		(197)		(357)		22
Other comprehensive income (loss), before Reclassifications, Net of Tax					0		(170)
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax					7		(49)
Other Comprehensive Income (Loss), Net of Tax					7		(219)
Pension Plan [Member]
Accumulated Other Comprehensive (Loss) Income, Net of Tax	(6,523)		(8,298)	[1]	(6,523)		(8,298)	[1]	(6,720)		(7,043)	[1]
Other comprehensive income (loss), before Reclassifications, Net of Tax					(47)		(1,564)	[1]
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax					244		309	[1]
Other Comprehensive Income (Loss), Net of Tax					197		(1,255)	[1]
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive (Loss) Income, Net of Tax	(2,190)	[2]	(2,260)	[3]	(2,190)	[2]	(2,260)	[3]	(2,843)	[2]	(2,333)	[3]
Other comprehensive income (loss), before Reclassifications, Net of Tax					653	[2]	73	[3]
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax					0	[2]	0	[3]
Other Comprehensive Income (Loss), Net of Tax					653	[2]	73	[3]
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive (Loss) Income, Net of Tax	(4)		10		(4)		10		7		(24)
Other comprehensive income (loss), before Reclassifications, Net of Tax					2		23
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax					(13)		11
Other Comprehensive Income (Loss), Net of Tax					(11)		34
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive (Loss) Income, Net of Tax	$ 2		$ (12)		2		(12)		$ 2		$ (18)
Other comprehensive income (loss), before Reclassifications, Net of Tax					1		(7)
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax					(1)		13
Other Comprehensive Income (Loss), Net of Tax					$ 0		$ 6

[1] The Pension Benefit Plans loss recognized in other comprehensive (loss) income during the six months ended June 30, 2016 includes the impact of the re-measurement of the principal U.S. pension plan as of June 30, 2016. See Note 14 for additional information.

[2] The cumulative translation adjustment gain for the six months ended June 30, 2017 is primarily driven by the weakening of the U.S. dollar (USD) against the European Euro (EUR).

[3] The cumulative translation adjustment gain for the six months ended June 30, 2016 is primarily driven by a modest weakening of the USD against the EUR and the Brazilian real (BRL).