Reconciliations of capital expenditures (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	$ 596	$ 450	$ 1,100	$ 998
Operating Segments | Reportable Segments
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	574	464	934	835
Operating Segments | Reportable Segments | Construction Industries
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	36	28	64	48
Operating Segments | Reportable Segments | Resource Industries
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	34	36	57	53
Operating Segments | Reportable Segments | Energy & Transportation
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	143	144	224	231
Operating Segments | Reportable Segments | Financial Products Segment
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	361	256	589	503
Intersegment Eliminations | All Other operating segments
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	32	23	47	38
Intersegment Eliminations | Cost Centers
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	0	6	19	15
Intersegment Eliminations | Timing
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	(15)	(14)	109	146
Intersegment Eliminations | Other
Reconciliation of Capital expenditures
Segment Reporting Information, Expenditure for Additions Long-Lived Assets	$ 5	$ (29)	$ (9)	$ (36)