Retirement Benefits (Unaudited) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Components of Net Periodic Benefit Cost
Net periodic benefit cost (benefit)			$ (154)	$ (597)
Defined contribution plan, employer contributions	$ 146	$ 122	361	321
Pension Benefits
Components of Net Periodic Benefit Cost
Service cost	59	92	118	184
Interest cost	392	284	784	568
Expected return on plan assets	(525)	(661)	(1,049)	(1,321)
Amortization of prior service credit	0	0	0	0
Net periodic benefit cost (benefit)	(74)	(285)	(147)	(569)
Defined benefit plan, contributions by Employer	25	25	54	51
OPB
Components of Net Periodic Benefit Cost
Service cost	1	2	2	4
Interest cost	16	12	33	24
Expected return on plan assets	(21)	(27)	(42)	(55)
Amortization of prior service credit	0	(1)	0	(1)
Net periodic benefit cost (benefit)	(4)	(14)	(7)	(28)
Defined benefit plan, contributions by Employer	$ 10	$ 10	$ 21	$ 20