Employee Benefit Plans (Significant Unobservable Inputs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Pension Benefits
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	$ 10,971	$ 11,256
Purchases, sales, issuances and settlements, net	(38)	(35)
Estimated fair value of plan assets at December 31,	8,294	10,971
Pension Benefits | Foreign government
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	1,116
Estimated fair value of plan assets at December 31,	769	1,116
Pension Benefits | Other (1)
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	783
Estimated fair value of plan assets at December 31,	693	783
Pension Benefits | Equity Securities
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	895
Estimated fair value of plan assets at December 31,	570	895
Pension Benefits | Corporate fixed maturity securities
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	4,305
Estimated fair value of plan assets at December 31,	3,001	4,305
Other Postretirement Benefits
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	1,443	1,492
Purchases, sales, issuances and settlements, net	0	(1)
Estimated fair value of plan assets at December 31,	1,303	1,443
Other Postretirement Benefits | Foreign government
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	51
Estimated fair value of plan assets at December 31,	61	51
Other Postretirement Benefits | Other (1)
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	59
Estimated fair value of plan assets at December 31,	44	59
Other Postretirement Benefits | Equity Securities
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	55
Estimated fair value of plan assets at December 31,	47	55
Other Postretirement Benefits | Corporate fixed maturity securities
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	222
Estimated fair value of plan assets at December 31,	205	222
Level 3 | Pension Benefits
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	967
Estimated fair value of plan assets at December 31,	920	967
Level 3 | Pension Benefits | Foreign government
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	1	0
Realized gains (losses)	0	0
Unrealized gains (losses)	0	0
Purchases, sales, issuances and settlements, net	0	1
Transfers into and/or out of Level 3	(1)	0
Estimated fair value of plan assets at December 31,	0	1
Level 3 | Pension Benefits | Other (1)
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	1	0
Realized gains (losses)	0	0
Unrealized gains (losses)	0	0
Purchases, sales, issuances and settlements, net	3	1
Transfers into and/or out of Level 3	(1)	0
Estimated fair value of plan assets at December 31,	3	1
Level 3 | Pension Benefits | Equity Securities
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	11	0
Realized gains (losses)	0	0
Unrealized gains (losses)	0	0
Purchases, sales, issuances and settlements, net	(8)	11
Transfers into and/or out of Level 3	0	0
Estimated fair value of plan assets at December 31,	3	11
Level 3 | Pension Benefits | Other investments
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	954	708
Realized gains (losses)	0	0
Unrealized gains (losses)	54	63
Purchases, sales, issuances and settlements, net	(153)	183
Transfers into and/or out of Level 3	0	0
Estimated fair value of plan assets at December 31,	855	954
Level 3 | Pension Benefits | Corporate fixed maturity securities
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	0	0
Realized gains (losses)	0	0
Unrealized gains (losses)	(1)	0
Purchases, sales, issuances and settlements, net	56	0
Transfers into and/or out of Level 3	0	0
Estimated fair value of plan assets at December 31,	55	0
Level 3 | Pension Benefits | Derivative Financial Instruments, Assets
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	0	0
Realized gains (losses)	0	0
Unrealized gains (losses)	1	0
Purchases, sales, issuances and settlements, net	3	0
Transfers into and/or out of Level 3	0	0
Estimated fair value of plan assets at December 31,	4	0
Level 3 | Other Postretirement Benefits
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	0
Estimated fair value of plan assets at December 31,	0	0
Level 3 | Other Postretirement Benefits | Foreign government
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	0
Estimated fair value of plan assets at December 31,	0	0
Level 3 | Other Postretirement Benefits | Other (1)
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	0
Estimated fair value of plan assets at December 31,	0	0
Level 3 | Other Postretirement Benefits | Equity Securities
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	0
Estimated fair value of plan assets at December 31,	0	0
Level 3 | Other Postretirement Benefits | Corporate fixed maturity securities
Rollforward fair value measurement using significant unobservable inputs (level 3) [Roll Forward]
Estimated fair value of plan assets at January 1,	0
Estimated fair value of plan assets at December 31,	$ 0	$ 0