Retirement Benefits (Unaudited) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Components of Net Periodic Benefit Cost
Net periodic benefit cost (benefit)			$ (597)	$ (546)
Defined contribution plan, employer contributions	$ 122	$ 111	321	377
Pension Benefits
Components of Net Periodic Benefit Cost
Service cost	92	103	184	207
Interest cost	284	264	568	527
Expected return on plan assets	(661)	(629)	(1,321)	(1,257)
Amortization of prior service credit	0	2	0	4
Net periodic benefit cost (benefit)	(285)	(264)	(569)	(527)
Defined benefit plan, contributions by Employer	25	26	51	53
OPB
Components of Net Periodic Benefit Cost
Service cost	2	4	4	8
Interest cost	12	14	24	27
Expected return on plan assets	27	27	55	53
Amortization of prior service credit	(1)	(1)	(1)	(1)
Net periodic benefit cost (benefit)	(14)	(10)	(28)	(19)
Defined benefit plan, contributions by Employer	$ 10	$ 10	$ 20	$ 21