Short-term borrowings (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Short-term borrowings:
Short-term borrowings	$ 5,166	$ 5,723
Notes payable to banks
Short-term borrowings:
Weighted-average interest rates on short-term borrowings (as a percent)	5.00%	5.30%
Commercial paper
Short-term borrowings:
Weighted-average interest rates on short-term borrowings (as a percent)	1.30%	2.00%
Demand notes
Short-term borrowings:
Weighted-average interest rates on short-term borrowings (as a percent)	1.70%	2.20%
Machinery, Energy & Transportation
Short-term borrowings:
Short-term borrowings	$ 5	$ 0
Machinery, Energy & Transportation | Notes payable to banks
Short-term borrowings:
Short-term borrowings	5	0
Financial Products
Short-term borrowings:
Short-term borrowings	5,161	5,723
Financial Products | Notes payable to banks
Short-term borrowings:
Short-term borrowings	605	526
Financial Products | Commercial paper
Short-term borrowings:
Short-term borrowings	4,168	4,759
Financial Products | Demand notes
Short-term borrowings:
Short-term borrowings	$ 388	$ 438