Derivative financial instruments and risk management (Details 5) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Offsetting Assets
Gross Amount of Recognized Assets	$ 131	$ 74
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amount of Assets Presented in the Statement of Financial Position	131	74
Financial Instruments	(53)	(32)
Cash Collateral Received	0	0
Net Amount of Assets	78	42
Machinery, Energy & Transportation
Offsetting Assets
Gross Amount of Recognized Assets	19	52
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amount of Assets Presented in the Statement of Financial Position	19	52
Financial Instruments	(19)	(22)
Cash Collateral Received	0	0
Net Amount of Assets	0	30
Financial Products
Offsetting Assets
Gross Amount of Recognized Assets	112	22
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amount of Assets Presented in the Statement of Financial Position	112	22
Financial Instruments	(34)	(10)
Cash Collateral Received	0	0
Net Amount of Assets	$ 78	$ 12