Shareowners' Equity (Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Benefit (provision) for income taxes	$ (18)	$ (135)	$ (302)	$ (7,227)
Other comprehensive income, net of tax	481	1,214	2,117	1,144
Less Other comprehensive income (loss) attributable to noncontrolling interests	5	(8)	10	(45)
Accumulated Other Comprehensive Income (Loss) Ending balance	(14,422)	(16,983)	(14,422)	(16,983)
Investment Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) Beginning balance	1,077	564	460	1,013
Other comprehensive income (OCI) before reclassifications - net of deferred taxes	97	22	675	(382)
OCI before reclassification tax	48	14	352	(196)
Benefit (provision) for income taxes	5	(20)	36	(45)
Reclassification from OCI net of deferred taxes	1	(26)	40	(70)
Other comprehensive income, net of tax	97	(3)	715	(452)
Less Other comprehensive income (loss) attributable to noncontrolling interests	(2)	0	(1)	0
Accumulated Other Comprehensive Income (Loss) Ending balance	1,176	561	1,176	561
Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) Beginning balance	(5,448)	(5,913)	(5,499)	(2,428)
Other comprehensive income (OCI) before reclassifications - net of deferred taxes	(280)	(108)	(138)	(3,936)
OCI before reclassification tax	5	(185)	222	1,158
Benefit (provision) for income taxes	(6)	(628)	74	(779)
Reclassification from OCI net of deferred taxes	85	733	1	1,039
Other comprehensive income, net of tax	(194)	624	(138)	(2,895)
Less Other comprehensive income (loss) attributable to noncontrolling interests	0	(8)	6	(43)
Accumulated Other Comprehensive Income (Loss) Ending balance	(5,643)	(5,281)	(5,643)	(5,281)
Cash Flow Hedge
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) Beginning balance	(51)	(140)	(80)	(180)
Other comprehensive income (OCI) before reclassifications - net of deferred taxes	(21)	(133)	(61)	(626)
OCI before reclassification tax	(12)	(28)	(17)	(24)
Benefit (provision) for income taxes	6	11	7	59
Reclassification from OCI net of deferred taxes	52	98	121	632
Other comprehensive income, net of tax	30	(35)	60	6
Less Other comprehensive income (loss) attributable to noncontrolling interests	0	0	0	0
Accumulated Other Comprehensive Income (Loss) Ending balance	(21)	(174)	(21)	(174)
Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) Beginning balance	(10,476)	(12,716)	(11,410)	(16,578)
Other comprehensive income, net of tax	548	627	1,481	4,486
Prior Service credit (costs)- net of deferred taxes	0	0	23	2,090
Net actuarial gain (loss), Tax	49	0	6	269
Net actuarial gain (loss) - net of deferred taxes	83	43	71	602
Prior service credit (costs), tax	0	0	5	1,194
Net curtailment/settlement, tax	0	0	0	(44)
Net curtailment/settlement - net of deferred taxes	0	0	(1)	(77)
Prior service cost amortization, tax	22	17	63	92
Prior service cost amortization - net of deferred taxes	12	0	45	101
Net actuarial loss amortization, tax	216	297	649	902
Net actuarial loss amortization - net of deferred taxes	453	584	1,343	1,771
Less Other comprehensive income (loss) attributable to noncontrolling interests	6	0	5	(2)
Accumulated Other Comprehensive Income (Loss) Ending balance	$ (9,934)	$ (12,089)	$ (9,934)	$ (12,089)