Benefit Plans (Movements in Other Comprehensive Earnings/Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Amortization:
Net loss (gain)	$ 8	$ 127	$ 163
Prior service cost (credit)	(34)	(39)	(41)
Deferred income taxes	8	(22)	(30)
Amounts reclassified to net earnings as components of net periodic benefit cost	(18)	66	92
Other movements during the year:
Net (loss) gain	(51)	147	624
Prior service (cost) credit	3	(2)	337
Deferred income taxes	9	(35)	(245)
Other movements	(39)	110	716
Total movements in other comprehensive earnings (losses)	(57)	176	808
Pension [Member]
Amortization:
Net loss (gain)	4	96	131
Prior service cost (credit)	6	6	5
Deferred income taxes	(2)	(26)	(35)
Amounts reclassified to net earnings as components of net periodic benefit cost	8	76	101
Other movements during the year:
Net (loss) gain	(60)	(183)	465
Prior service (cost) credit	0	0	(8)
Deferred income taxes	16	48	(118)
Other movements	(44)	(135)	339
Total movements in other comprehensive earnings (losses)	(36)	(59)	440
Postretirement Benefit Plan [Member]
Amortization:
Net loss (gain)	(2)	18	22
Prior service cost (credit)	(40)	(45)	(46)
Deferred income taxes	11	7	7
Amounts reclassified to net earnings as components of net periodic benefit cost	(31)	(20)	(17)
Other movements during the year:
Net (loss) gain	20	345	157
Prior service (cost) credit	3	(2)	345
Deferred income taxes	(10)	(87)	(127)
Other movements	13	256	375
Total movements in other comprehensive earnings (losses)	(18)	236	358
Postemployment Retirement Benefits [Member]
Amortization:
Net loss (gain)	6	13	10
Prior service cost (credit)	0	0	0
Deferred income taxes	(1)	(3)	(2)
Amounts reclassified to net earnings as components of net periodic benefit cost	5	10	8
Other movements during the year:
Net (loss) gain	(11)	(15)	2
Prior service (cost) credit	0	0	0
Deferred income taxes	3	4	0
Other movements	(8)	(11)	2
Total movements in other comprehensive earnings (losses)	$ (3)	$ (1)	$ 10