Reconciliations of depreciation and amortization (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Reconciliation of Depreciation and amortization
Depreciation and amortization	$ 593	$ 593	$ 1,766	$ 1,815
Operating Segments | Reportable Segments
Reconciliation of Depreciation and amortization
Depreciation and amortization	500	487	1,489	1,514
Operating Segments | Reportable Segments | Construction Industries
Reconciliation of Depreciation and amortization
Depreciation and amortization	60	61	178	183
Operating Segments | Reportable Segments | Resource Industries
Reconciliation of Depreciation and amortization
Depreciation and amortization	101	105	301	312
Operating Segments | Reportable Segments | Energy & Transportation
Reconciliation of Depreciation and amortization
Depreciation and amortization	144	147	428	442
Operating Segments | Reportable Segments | Financial Products Segment
Reconciliation of Depreciation and amortization
Depreciation and amortization	195	174	582	577
Intersegment Eliminations | All Other operating segments
Reconciliation of Depreciation and amortization
Depreciation and amortization	59	71	181	196
Intersegment Eliminations | Cost Centers
Reconciliation of Depreciation and amortization
Depreciation and amortization	24	31	74	96
Intersegment Eliminations | Other
Reconciliation of Depreciation and amortization
Depreciation and amortization	$ 10	$ 4	$ 22	$ 9