Reconciliations of capital expenditures (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Reconciliation of Capital expenditures
Capital expenditures	$ 493	$ 631	$ 1,491	$ 1,856
Reportable Segments
Reconciliation of Capital expenditures
Capital expenditures	427	617	1,262	1,667
All Other operating segments
Reconciliation of Capital expenditures
Capital expenditures	46	34	84	69
Cost Centers
Reconciliation of Capital expenditures
Capital expenditures	8	22	23	71
Timing
Reconciliation of Capital expenditures
Capital expenditures	1	(21)	147	108
Other
Reconciliation of Capital expenditures
Capital expenditures	11	(21)	(25)	(59)
Construction Industries | Reportable Segments
Reconciliation of Capital expenditures
Capital expenditures	37	48	85	117
Resource Industries | Reportable Segments
Reconciliation of Capital expenditures
Capital expenditures	10	31	63	91
Energy & Transportation | Reportable Segments
Reconciliation of Capital expenditures
Capital expenditures	100	150	331	366
Financial Products Segment | Reportable Segments
Reconciliation of Capital expenditures
Capital expenditures	$ 280	$ 388	$ 783	$ 1,093