Reconciliation of assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of assets
Segment assets	$ 78,324	$ 78,453
Consolidating Adjustments
Reconciliation of assets
Inventory Methodology Difference	(2,536)	(2,426)
Consolidating Adjustments | Cash and Short Term Investments
Reconciliation of assets
Segment assets	8,822	7,299
Consolidating Adjustments | Deferred Income Taxes
Reconciliation of assets
Segment assets	1,413	1,294
Consolidating Adjustments | Goodwill and Intangible Assets
Reconciliation of assets
Segment assets	4,847	4,435
Consolidating Adjustments | Property Plant and Equipment-Net and Other Assets
Reconciliation of assets
Segment assets	2,833	2,529
Consolidating Adjustments | Liabilities Included in Segment Assets
Reconciliation of assets
Segment assets	8,466	8,541
Consolidating Adjustments | Other
Reconciliation of assets
Segment assets	(392)	(414)
Operating Segments | Reportable Subsegments
Reconciliation of assets
Segment assets	53,154	55,467
Operating Segments | All Other operating segments
Reconciliation of assets
Segment assets	1,717	1,728
Construction Industries | Operating Segments | Reportable Subsegments
Reconciliation of assets
Segment assets	4,259	4,601
Resource Industries | Operating Segments | Reportable Subsegments
Reconciliation of assets
Segment assets	6,035	6,505
Energy & Transportation | Operating Segments | Reportable Subsegments
Reconciliation of assets
Segment assets	8,582	8,548
Financial Products Segment | Operating Segments | Reportable Subsegments
Reconciliation of assets
Segment assets	$ 34,278	$ 35,813