Employee Pension and Other Postretirement Benefits Net Benefit Costs (Table) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Pension Benefits
Defined Benefit Plan Disclosure
Service cost	$ 45	$ 36	$ 135	$ 108
Interest cost	64	69	193	208
Expected return on plan assets	(122)	(102)	(365)	(305)
Amortization of prior service cost (credit)	3	4	9	13
Amortization of net actuarial loss (gain)	28	29	82	85
Net periodic benefit cost	18	36	54	109
Other Benefits
Defined Benefit Plan Disclosure
Service cost	2	2	7	5
Interest cost	4	5	12	15
Amortization of prior service cost (credit)	(5)	(5)	(16)	(16)
Amortization of net actuarial loss (gain)	(2)	(3)	(5)	(8)
Net periodic benefit cost	$ (1)	$ (1)	$ (2)	$ (4)