Retirement Benefits Net Periodic Benefit Cost (Benefit) (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Mark-to-market pension and OPB benefit (expense)	$ 2,355	$ (1,034)	$ (1,800)
Net periodic benefit cost (benefit)	(1,091)	(802)	(432)
Pension Benefits
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Service cost	414	409	367
Interest cost	1,054	1,226	1,360
Expected return on plan assets	(2,512)	(2,376)	(2,101)
Amortization of prior service (credit) cost	(9)	(59)	(59)
Mark-to-market pension and OPB benefit (expense)	1,921	(1,034)	(1,783)
Other	(1)	10	0
Net periodic benefit cost (benefit)	(2,975)	244	1,350
Medical and Life Benefits
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Service cost	16	17	16
Interest cost	53	67	80
Expected return on plan assets	(105)	(102)	(92)
Amortization of prior service (credit) cost	(1)	4	(3)
Mark-to-market pension and OPB benefit (expense)	434	0	(17)
Other	0	2	0
Net periodic benefit cost (benefit)	$ (471)	$ (12)	$ 18