Retirement Benefits Categorization of Plan Assets (Details 7) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	$ 30,146	$ 37,824
Cash and cash equivalents
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	1,191	2,387
U.S. equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,139	3,087
International equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	1,784	3,108
U.S. Treasuries
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,999	2,836
U.S. Government Agency
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	145	180
Non-U.S. Government
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	172	277
Corporate debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	4,745	5,531
Asset backed
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	353	987
High yield debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	31	50
Bank loans
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	13	21
Other assets
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	4	92
Notes Payable, Other Payables [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	(25)	(73)
Level 1
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	4,099	6,412
Level 1 | Cash and cash equivalents
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	115	119
Level 1 | U.S. equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,138	3,085
Level 1 | International equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	1,784	3,105
Level 1 | U.S. Treasuries
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	22	21
Level 1 | Corporate debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	28	30
Level 1 | High yield debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	12	19
Level 1 | Other assets
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets		33
Level 2
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	9,475	12,139
Level 2 | Cash and cash equivalents
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	1,076	2,268
Level 2 | U.S. equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	1	2
Level 2 | U.S. Treasuries
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,977	2,815
Level 2 | U.S. Government Agency
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	145	180
Level 2 | Non-U.S. Government
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	172	277
Level 2 | Corporate debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	4,717	5,501
Level 2 | Asset backed
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	353	987
Level 2 | High yield debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	19	31
Level 2 | Bank loans
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	13	21
Level 2 | Other assets
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2	57
Level 3
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2	5
Level 3 | International equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	0	3
Level 3 | Other assets
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2	2
Fair Value Measured at Net Asset Value Per Share | U.S. equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	1,043	1,652
Fair Value Measured at Net Asset Value Per Share | International equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	3,904	6,849
Fair Value Measured at Net Asset Value Per Share | Fixed Income Funds
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,569	1,461
Fair Value Measured at Net Asset Value Per Share | Hedge Funds
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	44	63
Fair Value Measured at Net Asset Value Per Share | OpportunisticFunds
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,983	3,039
Fair Value Measured at Net Asset Value Per Share | Private Equity Funds [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	3,299	3,535
Fair Value Measured at Net Asset Value Per Share | Real Estate Funds [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,753	2,742
Pension and Other Post-retirement benefit plans [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Derivative Asset	71	78
Derivative Liability	(117)	(38)
Derivative, Notional Amount	$ 3,200	$ 3,700