Shareholders' Equity (Accumulated other comprehensive income) (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2022		Sep. 30, 2021		Sep. 30, 2022	Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	$ (11,487)		$ (16,661)		$ (11,659)	$ (17,133)
OCI before reclassifications	[1]	(158)		1,501		(284)	1,554
Amounts reclassified from AOCI	[1]	127		342		425	761
Net current period Other comprehensive income/(loss)	[1]	(31)		1,843		141	2,315
Ending Balance	[1]	(11,518)		(14,818)		(11,518)	(14,818)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax		155		227		469	690
Amortization of actuarial losses included in net periodic pension cost, tax		(45)		(60)		(129)	(182)
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net						39
Loss on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Tax						11
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(157)		(52)		(105)	(30)
OCI before reclassifications		(71)		(41)		(123)	(63)
Net current period Other comprehensive income/(loss)		(71)		(41)		(123)	(63)
Ending Balance		(228)		(93)		(228)	(93)
Unrealized Gains and Losses on Certain Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		1		1		1	1
OCI before reclassifications		(2)				(2)
Net current period Other comprehensive income/(loss)		(2)				(2)
Ending Balance		(1)		1		(1)	1
Unrealized Gains and Losses on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(38)		20		6	(43)
OCI before reclassifications		(83)		(1)		(157)	64
Amounts reclassified from AOCI		(6)		(4)		24	(6)
Net current period Other comprehensive income/(loss)		(89)		(5)		(133)	58
Ending Balance		(127)		15		(127)	15
Defined Benefit Pension Plans and Other Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(11,293)		(16,630)		(11,561)	(17,061)
OCI before reclassifications		(2)		1,543		(2)	1,553
Amounts reclassified from AOCI		133	[2]	346	[2]	401	767
Net current period Other comprehensive income/(loss)		131		1,889		399	2,320
Ending Balance		$ (11,162)		$ (14,741)		$ (11,162)	$ (14,741)

[1] Net of tax.(2)    Primarily relates to remeasurement of assets and benefit obligations related to the Company's pension plans resulting in an actuarial gain for the nine and three months ended September 30, 2021 of $1,551 and $1,544 (net of tax of ($106) and ($104)). See Note 12.

[2] Primarily relates to amortization of actuarial losses for the nine and three months ended September 30, 2022 of $469 and $155 (net of tax of ($129) and ($45)) and the nine and three months ended September 30, 2021 totaling $690 and $227 (net of tax of ($182) and ($60)). These are included in the net periodic pension cost.