Employee Benefit Plans, Pre-Tax Amounts Recognized in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net (gain) loss reclassified into income:
Total changes in other comprehensive income	$ 378	$ (80)	$ (234)
Pension Plans [Member]
Net gain (loss) arising during the year:
Net actuarial gain (loss)	308	(105)	(204)
Prior service cost	(4)	(5)	0
Net (gain) loss reclassified into income:
Net actuarial (gain) loss	81	74	41
Prior service credit	(18)	(19)	(19)
Curtailment and settlement loss	8	5	4
Effect of exchange rates	2	0	0
Total changes in other comprehensive income	377	(50)	(178)
Other Postretirement Benefit Plans [Member]
Net gain (loss) arising during the year:
Net actuarial gain (loss)	9	(23)	(41)
Prior service cost	0	0	(3)
Net (gain) loss reclassified into income:
Net actuarial (gain) loss	(1)	0	(3)
Prior service credit	(7)	(7)	(9)
Curtailment and settlement loss	0	0	0
Effect of exchange rates	0	0	0
Total changes in other comprehensive income	$ 1	$ (30)	$ (56)