Income taxes (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of profit (loss) before taxes
U.S	$ 240	$ (2,053)	$ 636
Non-U.S	3,842	2,192	2,803
Consolidated profit before taxes	4,082	139	3,439
Current tax provision (benefit):
U.S.	963	(90)	525
Non-U.S.	1,124	718	656
State (U.S.)	39	(5)	42
Current tax provision (benefit)	2,126	623	1,223
Deferred tax provision (benefit):
U.S.	1,385	(544)	(367)
Non-U.S.	(17)	(108)	66
State (U.S.)	(155)	221	(6)
Deferred tax provision (benefit)	1,213	(431)	(307)
Provision (benefit) for income taxes	3,339	192	916
Income Taxes Paid	$ 1,404	$ 522	$ 1,143