Derivative financial instruments and risk management (Details 6) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Offsetting Liabilities
Cash collateral received or pledged under master netting agreements		$ 0
Gross Amount of Recognized Liabilities	$ (71)	(150)
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amount of Liabilities Presented in the Statement of Financial Position	(71)	(150)
Financial Instruments	34	53
Cash Collateral Pledged	0	0
Net Amount of Liabilities	37	97
Machinery, Energy & Transportation
Offsetting Liabilities
Gross Amount of Recognized Liabilities	(21)	(87)
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amount of Liabilities Presented in the Statement of Financial Position	(21)	(87)
Financial Instruments	13	19
Cash Collateral Pledged	0	0
Net Amount of Liabilities	8	68
Financial Products
Offsetting Liabilities
Gross Amount of Recognized Liabilities	(50)	(63)
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amount of Liabilities Presented in the Statement of Financial Position	(50)	(63)
Financial Instruments	21	34
Cash Collateral Pledged	0	0
Net Amount of Liabilities	$ 29	$ 29