Postretirement benefits Schedule of amounts recognized in AOCI on a pretax basis (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Pension Plan [Member] | UNITED STATES
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial loss (gain)	$ (15)	$ (227)
Prior Service Cost (benefit)	0	0
Total	(15)	(227)
Pension Plan [Member] | Non-US [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial loss (gain)	112	82
Prior Service Cost (benefit)	9	6
Total	121	88
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial loss (gain)	0	12
Prior Service Cost (benefit)	(200)	(288)
Total	$ (200)	$ (276)