Accumulated Other Comprehensive Income/(Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Derivative instruments [Abstract]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$ 165
Pension and other postretirement benefits
Total AOCI ending balance at June 30	(8,471)		$ (8,471)		$ (7,728)
Parent Company [Member]
Foreign currency transaction [Abstract]
Beginning balance	(6,079)	$ (4,557)	(4,626)	$ (4,800)
Gains/(Losses) on foreign currency translation	(141)	(139)	(1,547)	132
Less: Tax/(Tax benefit)	(50)	(12)	(23)	16
Net gains/(losses) on foreign currency translation	(91)	(127)	(1,524)	116
(Gains)/Losses reclassified from AOCI to income	(11)	0	(31)	0
Other comprehensive income/(loss), net of tax	(102)	(127)	(1,555)	116
Ending balance	(6,181)	(4,684)	(6,181)	(4,684)
Marketable securities [Abstract]
Beginning balance	85	4	71	(59)
Gains/(Losses) on available for sale securities	146	74	165	154
Less: Tax/(Tax benefit)	33	17	38	36
Net gains/(losses) on available for sale securities	113	57	127	118
(Gains)/Losses reclassified from AOCI to net income	(18)	2	(18)	5
Less: Tax/(Tax benefit)	(4)	0	(4)	1
Net (gains)/losses reclassified from AOCI to net income	(14)	2	(14)	4
Other comprehensive income/(loss), net of tax	99	59	113	122
Ending balance	184	63	184	63
Derivative instruments [Abstract]
Beginning balance	204	(245)	(488)	201
Gains/(Losses) on available for sale securities	(64)	168	732	(342)
Less: Tax/(Tax benefit)	(23)	24	150	(78)
Net gains/(losses) on available for sale securities	(41)	144	582	(264)
(Gains)/Losses reclassified from AOCI to net income	18	(38)	102	(87)
Less: Tax/(Tax benefit)	1	(11)	16	(22)
Net (gains)/losses reclassified from AOCI to net income	17	(27)	86	(65)
Other comprehensive income/(loss), net of tax	(24)	117	668	(329)
Ending balance	180	(128)	180	(128)
Pension and other postretirement benefits
Beginning balance	(2,671)	(2,703)	(2,685)	(2,708)
Amortization of prior service costs/(credits)	22	13	26	25
Less: Tax/(Tax benefit)	3	3	4	5
Net prior service costs/(credits) reclassified from AOCI to net income	19	10	22	20
Translation impact on non-U.S. plans	(2)	6	9	1
Other comprehensive income/(loss), net of tax	17	16	31	21
Ending balance	(2,654)	(2,687)	(2,654)	(2,687)
Total AOCI ending balance at June 30	$ (8,471)	$ (7,436)	$ (8,471)	$ (7,436)