Reconciliations of depreciation and amortization (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Reconciliation of Depreciation and amortization
Depreciation and amortization	$ 593	$ 645	$ 1,815	$ 1,933
Reportable Segments
Reconciliation of Depreciation and amortization
Depreciation and amortization	487	552	1,514	1,643
All Other operating segments
Reconciliation of Depreciation and amortization
Depreciation and amortization	71	53	196	158
Cost Centers
Reconciliation of Depreciation and amortization
Depreciation and amortization	31	35	96	100
Other
Reconciliation of Depreciation and amortization
Depreciation and amortization	4	5	9	32
Construction Industries | Reportable Segments
Reconciliation of Depreciation and amortization
Depreciation and amortization	61	73	183	220
Resource Industries | Reportable Segments
Reconciliation of Depreciation and amortization
Depreciation and amortization	105	113	312	337
Energy & Transportation | Reportable Segments
Reconciliation of Depreciation and amortization
Depreciation and amortization	147	157	442	464
Financial Products Segment | Reportable Segments
Reconciliation of Depreciation and amortization
Depreciation and amortization	$ 174	$ 209	$ 577	$ 622