Segment information (Details 5) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of assets
Total assets	$ 76,962	$ 74,704	$ 78,342
Reportable segments
Reconciliation of assets
Total assets	53,698	55,517	59,605
All Other operating segments
Reconciliation of assets
Total assets	1,312	1,381	1,405
Cash and Short Term Investments
Reconciliation of assets
Total assets	7,381	5,257	5,340
Intercompany Receivables
Reconciliation of assets
Total assets	0	0	0
Investment in Financial Products
Reconciliation of assets
Total assets	0	0	0
Deferred income taxes
Reconciliation of assets
Total assets	1,592	2,701	2,415
Goodwill and Intangible Assets
Reconciliation of assets
Total assets	4,210	3,883	3,571
Property Plant and Equipment-Net and Other Assets
Reconciliation of assets
Total assets	2,341	1,645	1,585
Operating Lease Methodology Difference
Reconciliation of assets
Total assets	(191)	(186)	(213)
Liabilities Included in Segment Assets
Reconciliation of assets
Total assets	9,352	7,400	8,017
Inventory Methodology Differences
Reconciliation of assets
Total assets	(2,287)	(2,373)	(2,646)
Other
Reconciliation of assets
Total assets	(446)	(521)	(737)
Consolidating Adjustments
Reconciliation of assets
Total assets	(6,404)	(6,354)	(5,845)
Consolidating Adjustments | Reportable segments
Reconciliation of assets
Total assets	0	0	0
Consolidating Adjustments | All Other operating segments
Reconciliation of assets
Total assets	0	0	0
Consolidating Adjustments | Cash and Short Term Investments
Reconciliation of assets
Total assets	0	0	0
Consolidating Adjustments | Intercompany Receivables
Reconciliation of assets
Total assets	(1,733)	(1,713)	(1,087)
Consolidating Adjustments | Investment in Financial Products
Reconciliation of assets
Total assets	(4,064)	(3,638)	(3,888)
Consolidating Adjustments | Deferred income taxes
Reconciliation of assets
Total assets	(574)	(947)	(793)
Consolidating Adjustments | Goodwill and Intangible Assets
Reconciliation of assets
Total assets	0	0	0
Consolidating Adjustments | Property Plant and Equipment-Net and Other Assets
Reconciliation of assets
Total assets	0	0	0
Consolidating Adjustments | Operating Lease Methodology Difference
Reconciliation of assets
Total assets	0	0	0
Consolidating Adjustments | Liabilities Included in Segment Assets
Reconciliation of assets
Total assets	0	0	0
Consolidating Adjustments | Inventory Methodology Differences
Reconciliation of assets
Total assets	0	0	0
Consolidating Adjustments | Other
Reconciliation of assets
Total assets	(33)	(56)	(77)
Machinery, Energy & Transportation | Reportable segments
Reconciliation of assets
Total assets	18,805	20,293	23,876
Machinery, Energy & Transportation | Business
Reconciliation of assets
Total assets	48,487	45,863	48,551
Machinery, Energy & Transportation | Business | Reportable segments
Reconciliation of assets
Total assets	18,805	20,293	23,876
Machinery, Energy & Transportation | Business | All Other operating segments
Reconciliation of assets
Total assets	1,312	1,381	1,405
Machinery, Energy & Transportation | Business | Cash and Short Term Investments
Reconciliation of assets
Total assets	7,381	5,257	5,340
Machinery, Energy & Transportation | Business | Intercompany Receivables
Reconciliation of assets
Total assets	1,733	1,713	1,087
Machinery, Energy & Transportation | Business | Investment in Financial Products
Reconciliation of assets
Total assets	4,064	3,638	3,888
Machinery, Energy & Transportation | Business | Deferred income taxes
Reconciliation of assets
Total assets	2,166	3,648	3,208
Machinery, Energy & Transportation | Business | Goodwill and Intangible Assets
Reconciliation of assets
Total assets	4,210	3,883	3,571
Machinery, Energy & Transportation | Business | Property Plant and Equipment-Net and Other Assets
Reconciliation of assets
Total assets	2,341	1,645	1,585
Machinery, Energy & Transportation | Business | Operating Lease Methodology Difference
Reconciliation of assets
Total assets	(191)	(186)	(213)
Machinery, Energy & Transportation | Business | Liabilities Included in Segment Assets
Reconciliation of assets
Total assets	9,352	7,400	8,017
Machinery, Energy & Transportation | Business | Inventory Methodology Differences
Reconciliation of assets
Total assets	(2,287)	(2,373)	(2,646)
Machinery, Energy & Transportation | Business | Other
Reconciliation of assets
Total assets	(399)	(436)	(567)
Financial Products | Business
Reconciliation of assets
Total assets	34,879	35,195	35,636
Financial Products | Business | Reportable segments
Reconciliation of assets
Total assets	34,893	35,224	35,729
Financial Products | Business | All Other operating segments
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Cash and Short Term Investments
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Intercompany Receivables
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Investment in Financial Products
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Deferred income taxes
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Goodwill and Intangible Assets
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Property Plant and Equipment-Net and Other Assets
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Operating Lease Methodology Difference
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Liabilities Included in Segment Assets
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Inventory Methodology Differences
Reconciliation of assets
Total assets	0	0	0
Financial Products | Business | Other
Reconciliation of assets
Total assets	$ (14)	$ (29)	$ (93)