Employee Pension and Other Postretirement Benefits Net Benefit Costs (Table) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Benefits
Defined Benefit Plan Disclosure
Service cost	$ 45	$ 36	$ 90	$ 72
Interest cost	65	70	129	139
Expected return on plan assets	(122)	(101)	(243)	(203)
Amortization of prior service cost (credit)	3	4	6	9
Amortization of net actuarial loss (gain)	27	28	54	56
Net periodic benefit cost	18	37	36	73
Other Benefits
Defined Benefit Plan Disclosure
Service cost	3	1	5	3
Interest cost	4	5	8	10
Amortization of prior service cost (credit)	(6)	(6)	(11)	(11)
Amortization of net actuarial loss (gain)	$ (1)	(2)	(3)	(5)
Net periodic benefit cost		$ (2)	$ (1)	$ (3)