Pension Plans and Other Post Employment Benefit Plans Components of net periodic benefit cost (credit) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost		$ 5	$ 20
Interest Cost		141	208
Expected return on plan assets		(251)	(304)
Amortization of unrecognized loss		1	1
Settlement Loss		2	0
Defined Benefit Plan, Net Periodic Benefit (Credit) Cost		(102)	(75)
Other Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost		1	2
Interest Cost		16	23
Discontinued Operations [Member] | Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Net Periodic Benefit (Credit) Cost	[1]	0	(8)
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax			(21)
Continuing Operations [Member] | Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Net Periodic Benefit (Credit) Cost		(102)	(67)
Continuing Operations [Member] | Other Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Net Periodic Benefit (Credit) Cost		$ 17	$ 25

[1] Includes non-service related components of net periodic benefit credit of $(21) million for the three months ended March 31, 2019.