Retirement Benefits (Unaudited) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Components of Net Periodic Benefit Cost
Net periodic benefit cost (benefit)			$ (169)	$ (226)
Defined contribution plan, employer contributions	$ 155	$ 151	384	381
Pension Benefits
Components of Net Periodic Benefit Cost
Service cost	54	59	108	119
Interest cost	402	382	805	763
Expected return on plan assets	(539)	(549)	(1,079)	(1,098)
Amortization of prior service credit			0	0
Other			7	0
Net periodic benefit cost (benefit)	(83)	(108)	(159)	(216)
Defined benefit plan, contributions by Employer	24	24	42	49
OPB
Components of Net Periodic Benefit Cost
Service cost	1	1	2	2
Interest cost	15	16	31	31
Expected return on plan assets	(21)	(22)	(42)	(43)
Amortization of prior service credit			(1)	0
Other			0	0
Net periodic benefit cost (benefit)	(5)	(5)	(10)	(10)
Defined benefit plan, contributions by Employer	$ 10	$ 9	$ 20	$ 20