Accumulated Other Comprehensive Income/(Loss) (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
Accumulated Other Comprehensive Income (Loss) [Abstract]
Total AOCI ending balance at June 30	$ (6,716)		$ (6,716)		$ (7,013)
Derivative instruments [Abstract]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	(270)
Parent Company [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Total AOCI ending balance at June 30	(6,716)	$ (5,976)	(6,716)	$ (5,976)
Foreign currency transaction [Abstract]
Beginning balance	(4,350)	(3,633)	(4,593)	(3,570)
Gains/(Losses) on foreign currency translation	(39)	(58)	150	(88)
Less: Tax/(Tax benefit)	(123)	0	(177)	0
Net gains/(losses) on foreign currency translation	84	(58)	327	(88)
(Gains)/Losses reclassified from AOCI to income	0	0	0	(33)
Other comprehensive income/(loss), net of tax	84	(58)	327	(121)
Ending balance	(4,266)	(3,691)	(4,266)	(3,691)
Marketable securities [Abstract]
Beginning balance	(15)	0	(14)	(6)
Gains/(Losses) on available for sale securities	2	0	3	11
Less: Tax/(Tax benefit)	2	0	5	0
Net gains/(losses) on available for sale securities	0	0	(2)	11
(Gains)/Losses reclassified from AOCI to net income	4	0	5	(1)
Less: Tax/(Tax benefit)	0	0	0	4
Net (gains)/losses reclassified from AOCI to net income	4	0	5	(5)
Other comprehensive income/(loss), net of tax	4	0	3	6
Ending balance	(11)	0	(11)	0
Derivative instruments [Abstract]
Beginning balance	116	310	283	64
Gains/(Losses) on available for sale securities	318	184	206	547
Less: Tax/(Tax benefit)	85	35	51	94
Net gains/(losses) on available for sale securities	233	149	155	453
(Gains)/Losses reclassified from AOCI to net income	(124)	(46)	(242)	(133)
Less: Tax/(Tax benefit)	(28)	(8)	(57)	(37)
Net (gains)/losses reclassified from AOCI to net income	(96)	(38)	(185)	(96)
Other comprehensive income/(loss), net of tax	137	111	(30)	357
Ending balance	253	421	253	421
Pension and other postretirement benefits
Beginning balance	(2,680)	(2,723)	(2,689)	(2,745)
Amortization of prior service costs/(credits)	15	16	30	33
Less: Tax/(Tax benefit)	23	7	28	10
Net prior service costs/(credits) reclassified from AOCI to net income	(8)	9	2	23
Translation impact on non-U.S. plans	(4)	8	(5)	16
Other comprehensive income/(loss), net of tax	(12)	17	(3)	39
Ending balance	$ (2,692)	$ (2,706)	$ (2,692)	$ (2,706)