Other Comprehensive Earnings/Losses (Changes in Each Component of Accumulated Other Comprehensive Losses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 2,925	$ 6,319
Other comprehensive earnings (losses), net of deferred income taxes	567	331
Ending balance	2,995	6,637
Accumulated Other Comprehensive Losses [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(4,341)	(2,864)
Other comprehensive earnings (losses) before reclassifications	712	400
Deferred income taxes	(151)	(85)
Other comprehensive earnings (losses) before reclassifications, net of deferred income taxes	561	315
Amounts reclassified to net earnings	10	21
Deferred income taxes	(4)	(5)
Amounts reclassified to net earnings, net of deferred income taxes	6	16
Other comprehensive earnings (losses), net of deferred income taxes	567	331
Ending balance	(3,774)	(2,533)
Benefit Plans [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(2,420)	(2,192)
Other comprehensive earnings (losses) before reclassifications	0	0
Deferred income taxes	0	0
Other comprehensive earnings (losses) before reclassifications, net of deferred income taxes	0	0
Amounts reclassified to net earnings	38	28
Deferred income taxes	(10)	(7)
Amounts reclassified to net earnings, net of deferred income taxes	28	21
Other comprehensive earnings (losses), net of deferred income taxes	28	21
Ending balance	(2,392)	(2,171)
ABI [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(1,938)	(693)
Other comprehensive earnings (losses) before reclassifications	690	388
Deferred income taxes	(151)	(85)
Other comprehensive earnings (losses) before reclassifications, net of deferred income taxes	539	303
Amounts reclassified to net earnings	(28)	(7)
Deferred income taxes	6	2
Amounts reclassified to net earnings, net of deferred income taxes	(22)	(5)
Other comprehensive earnings (losses), net of deferred income taxes	517	298
Ending balance	(1,421)	(395)
Currency Translation Adjustments and Other [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	17	21
Other comprehensive earnings (losses) before reclassifications	22	12
Deferred income taxes	0	0
Other comprehensive earnings (losses) before reclassifications, net of deferred income taxes	22	12
Amounts reclassified to net earnings	0	0
Deferred income taxes	0	0
Amounts reclassified to net earnings, net of deferred income taxes	0	0
Other comprehensive earnings (losses), net of deferred income taxes	22	12
Ending balance	$ 39	$ 33