Other Comprehensive Earnings/Losses (Changes in Each Component of Accumulated Other Comprehensive Losses) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 14,081	$ 15,397	$ 14,789	$ 15,380
Other comprehensive earnings (losses), net of deferred income taxes	71	275	(99)	245
Ending balance	14,466	15,798	14,466	15,798
Accumulated Other Comprehensive Losses [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(2,717)	(1,927)	(2,547)	(1,897)
Other comprehensive earnings (losses) before reclassifications	69	304	(169)	223
Deferred income taxes	(12)	(66)	37	(50)
Other comprehensive earnings (losses) before reclassifications, net of deferred income taxes	57	238	(132)	173
Amounts reclassified to net earnings	20	50	47	98
Deferred income taxes	(6)	(13)	(14)	(26)
Amounts reclassified to net earnings, net of deferred income taxes	14	37	33	72
Other comprehensive earnings (losses), net of deferred income taxes	71	275	(99)	245
Ending balance	(2,646)	(1,652)	(2,646)	(1,652)
Benefit Plans [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(2,139)	(1,794)	(2,168)	(1,839)
Other comprehensive earnings (losses) before reclassifications	0	0	0	0
Deferred income taxes	0	0	0	0
Other comprehensive earnings (losses) before reclassifications, net of deferred income taxes	0	0	0	0
Amounts reclassified to net earnings	39	57	78	118
Deferred income taxes	(10)	(15)	(20)	(31)
Amounts reclassified to net earnings, net of deferred income taxes	29	42	58	87
Other comprehensive earnings (losses), net of deferred income taxes	29	42	58	87
Ending balance	(2,110)	(1,752)	(2,110)	(1,752)
ABI [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(573)	(129)	(374)	(54)
Other comprehensive earnings (losses) before reclassifications	56	306	(182)	225
Deferred income taxes	(10)	(66)	39	(50)
Other comprehensive earnings (losses) before reclassifications, net of deferred income taxes	46	240	(143)	175
Amounts reclassified to net earnings	(19)	(7)	(31)	(20)
Deferred income taxes	4	2	6	5
Amounts reclassified to net earnings, net of deferred income taxes	(15)	(5)	(25)	(15)
Other comprehensive earnings (losses), net of deferred income taxes	31	235	(168)	160
Ending balance	(542)	106	(542)	106
Currency Translation Adjustments and Other [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(5)	(4)	(5)	(4)
Other comprehensive earnings (losses) before reclassifications	13	(2)	13	(2)
Deferred income taxes	(2)	0	(2)	0
Other comprehensive earnings (losses) before reclassifications, net of deferred income taxes	11	(2)	11	(2)
Amounts reclassified to net earnings	0	0	0	0
Deferred income taxes	0	0	0	0
Amounts reclassified to net earnings, net of deferred income taxes	0	0	0	0
Other comprehensive earnings (losses), net of deferred income taxes	11	(2)	11	(2)
Ending balance	$ 6	$ (6)	$ 6	$ (6)