Retirement Benefits Net Periodic Benefit Cost (Benefit) (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Interest cost	$ 1,700
Mark-to-market pension and OPB benefit (expense)	527	$ 443	$ (422)
Net periodic benefit cost (benefit)	(346)	(438)	(308)
Pension Benefits
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Service cost	217	239	236
Interest cost	1,612	1,526	1,568
Expected return on plan assets	(2,159)	(2,197)	(2,098)
Amortization of prior service credit	0	0	0
Mark-to-market pension and OPB benefit (expense)	514	450	(442)
Other	6	15	0
Net periodic benefit cost (benefit)	(838)	(867)	148
Medical and Life Benefits
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Service cost	4	4	5
Interest cost	62	62	67
Expected return on plan assets	(85)	(87)	(85)
Amortization of prior service credit	(3)	0	(1)
Mark-to-market pension and OPB benefit (expense)	13	(7)	20
Other	0	0	0
Net periodic benefit cost (benefit)	$ (35)	$ (14)	$ (34)