Accumulated Other Comprehensive Income/(Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension and other postretirement benefits
Total AOCI ending balance at December 31	$ (7,013)	$ (6,257)
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	358
Parent Company [Member]
Foreign currency translation
Beginning balance	(3,570)	(2,438)	$ (2,402)
Gains/(Losses) on foreign currency translation	(494)	(969)	(206)
Less: Tax/(Tax benefit) (a)	537	177	(17)
Net gains/(losses) on foreign currency translation	(1,031)	(1,146)	(189)
(Gains)/Losses reclassified from AOCI to net income (b)	8	14	153
Other comprehensive income/(loss), net of tax	(1,023)	(1,132)	(36)
Ending balance	(4,593)	(3,570)	(2,438)
Marketable securities
Beginning balance	(6)	0	0
Gains/(Losses) on available for sale securities	(13)	(10)	0
Less: Tax/(Tax benefit)	(10)	(4)	0
Net gains/(losses) on available for sale securities	(3)	(6)	0
(Gains)/Losses reclassified from AOCI to net income	(1)	0	0
Less: Tax/(Tax benefit)	4		0
Net (gains)/losses reclassified from AOCI to net income	(5)	0	0
Other comprehensive income/(loss), net of tax	(8)	(6)	0
Ending balance	(14)	(6)	0
Derivative instruments
Beginning balance	64	(163)	19
Gains/(Losses) on derivative instruments	770	123	(271)
Less: Tax/(Tax benefit)	144	50	(96)
Net gains/(losses) on derivative instruments	626	73	(175)
(Gains)/Losses reclassified from AOCI to net income	(537)	239	(78)
Less: Tax/(Tax benefit)	(130)	85	(71)
Net (gains)/losses reclassified from AOCI to net income (c)	(407)	154	(7)
Other comprehensive income/(loss), net of tax	219	227	(182)
Ending balance	283	64	(163)
Pension and other postretirement benefits
Beginning balance	(2,745)	(2,664)	(2,641)
Prior service (costs)/credits arising during the period	(16)	(104)	(11)
Less: Tax/(Tax benefit)	(4)	(41)	(2)
Net prior service (costs)/credits arising during the period	(12)	(63)	(9)
Amortization and recognition of prior service costs/(credits) (d)	66	(2)	(19)
Less: Tax/(Tax benefit)	22	6	(7)
Net prior service costs/(credits) reclassified from AOCI to net income	44	(8)	(12)
Translation impact on non-U.S. plans	24	(10)	(2)
Other comprehensive income/(loss), net of tax	56	(81)	(23)
Ending balance	(2,689)	(2,745)	(2,664)
Total AOCI ending balance at December 31	$ (7,013)	$ (6,257)	$ (5,265)