Pension And Other Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Pension Benefits - U.S.
Service cost	$ 235	$ 175
Interest cost	177	193
Expected return on plan assets	(175)	(142)
Amortization of actuarial loss/(gain) and prior service cost	79	77
Net pension enhancement and curtailment/settlement cost	52	54
Net benefit cost	368	357
Pension Benefits - Non-U.S. [Member]
Service cost	175	139
Interest cost	161	192
Expected return on plan assets	(222)	(197)
Amortization of actuarial loss/(gain) and prior service cost	119	103
Net benefit cost	233	237
Other Postretirement Benefits [Member]
Service cost	45	33
Interest cost	70	79
Expected return on plan assets	(4)	(4)
Amortization of actuarial loss/(gain) and prior service cost	12	3
Net benefit cost	$ 123	$ 111