Segment information Sales and revenues by geographic region (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Sales and revenue by geographic region
Sales and revenues	$ 13,144	$ 12,758	$ 14,432	$ 13,466	$ 14,342	$ 13,510	$ 14,011	$ 12,859	$ 53,800	$ 54,722	$ 45,462
Reportable segments
Sales and revenue by geographic region
Sales and revenues									54,288	55,115	45,694
Other
Sales and revenue by geographic region
Sales and revenues											(410)
All Other operating segments
Sales and revenue by geographic region
Sales and revenues											178
Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									4,168	4,456	3,882
Construction Industries | Reportable segments
Sales and revenue by geographic region
Revenues									22,556	23,116
Sales and revenues									22,556	23,116	19,133
Construction Industries | Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									93	121	107
Resource Industries | Reportable segments
Sales and revenue by geographic region
Revenues									9,813	9,888
Sales and revenues									9,813	9,888	7,504
Resource Industries | Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									463	382	357
Energy & Transportation | Reportable segments
Sales and revenue by geographic region
Revenues									18,485	18,832
Sales and revenues									18,485	18,832	15,964
Energy & Transportation | Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									3,612	3,953	3,418
All Other | All Other operating segments
Sales and revenue by geographic region
Revenues									127	154
Machinery, Energy & Transportation
Sales and revenue by geographic region
Revenues									50,755	51,822
Machinery, Energy & Transportation | Reportable segments
Sales and revenue by geographic region
Sales and revenues									50,854	51,836	42,601
Machinery, Energy & Transportation | Intersegment Eliminations
Sales and revenue by geographic region
Revenues									(226)	(168)
Sales and revenues									4,168	4,456	3,882
Financial Products Segment | Reportable segments
Sales and revenue by geographic region
Sales and revenues									3,434	3,279	3,093
Financial Products Segment | Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									0	0	0
Financial Products
Sales and revenue by geographic region
Sales and revenues									3,045	2,900
Financial Products | Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									(389)	(379)
Business | Energy & Transportation | Reportable segments
Sales and revenue by geographic region
Sales and revenues									18,485	18,832
Business | Machinery, Energy & Transportation
Sales and revenue by geographic region
Sales and revenues											42,676
Business | Machinery, Energy & Transportation | Reportable segments
Sales and revenue by geographic region
Sales and revenues											42,601
Business | Machinery, Energy & Transportation | Other
Sales and revenue by geographic region
Sales and revenues											(103)
Business | Machinery, Energy & Transportation | All Other operating segments
Sales and revenue by geographic region
Sales and revenues											178
Business | Financial Products Segment
Sales and revenue by geographic region
Sales and revenues											3,167
Business | Financial Products Segment | Reportable segments
Sales and revenue by geographic region
Sales and revenues											3,093
Business | Financial Products Segment | Other
Sales and revenue by geographic region
Sales and revenues											74
Business | Financial Products Segment | All Other operating segments
Sales and revenue by geographic region
Sales and revenues											0
Consolidating Adjustments
Sales and revenue by geographic region
Sales and revenues											(381)
Consolidating Adjustments | Reportable segments
Sales and revenue by geographic region
Sales and revenues											0
Consolidating Adjustments | Other
Sales and revenue by geographic region
Sales and revenues											(381)
Consolidating Adjustments | All Other operating segments
Sales and revenue by geographic region
Sales and revenues											$ 0
North America
Sales and revenue by geographic region
Sales and revenues									25,785	25,623
North America | Machinery, Energy & Transportation | Intersegment Eliminations
Sales and revenue by geographic region
Revenues									(192)	(155)
North America | Financial Products | Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									(234)	(234)
North America | Business | Construction Industries | Reportable segments
Sales and revenue by geographic region
Revenues									11,455	10,754
North America | Business | Resource Industries | Reportable segments
Sales and revenue by geographic region
Revenues									3,632	3,357
North America | Business | Energy & Transportation | Reportable segments
Sales and revenue by geographic region
Revenues									8,864	9,685
North America | Business | All Other | All Other operating segments
Sales and revenue by geographic region
Revenues									25	63
North America | Business | Machinery, Energy & Transportation
Sales and revenue by geographic region
Revenues									23,784	23,704
North America | Business | Financial Products Segment | Reportable segments
Sales and revenue by geographic region
Sales and revenues									2,235	2,153
North America | Business | Financial Products
Sales and revenue by geographic region
Sales and revenues									2,001	1,919
Latin America
Sales and revenue by geographic region
Sales and revenues									4,710	4,695
Latin America | Machinery, Energy & Transportation | Intersegment Eliminations
Sales and revenue by geographic region
Revenues									0	0
Latin America | Financial Products | Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									(51)	(46)
Latin America | Business | Construction Industries | Reportable segments
Sales and revenue by geographic region
Revenues									1,533	1,479
Latin America | Business | Resource Industries | Reportable segments
Sales and revenue by geographic region
Revenues									1,533	1,647
Latin America | Business | Energy & Transportation | Reportable segments
Sales and revenue by geographic region
Revenues									1,389	1,331
Latin America | Business | All Other | All Other operating segments
Sales and revenue by geographic region
Revenues									7	3
Latin America | Business | Machinery, Energy & Transportation
Sales and revenue by geographic region
Revenues									4,462	4,460
Latin America | Business | Financial Products Segment | Reportable segments
Sales and revenue by geographic region
Sales and revenues									299	281
Latin America | Business | Financial Products
Sales and revenue by geographic region
Sales and revenues									248	235
EAME
Sales and revenue by geographic region
Sales and revenues									11,223	11,929
EAME | Machinery, Energy & Transportation | Intersegment Eliminations
Sales and revenue by geographic region
Revenues									(20)	(11)
EAME | Financial Products | Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									(35)	(26)
EAME | Business | Construction Industries | Reportable segments
Sales and revenue by geographic region
Revenues									4,012	4,410
EAME | Business | Resource Industries | Reportable segments
Sales and revenue by geographic region
Revenues									1,836	2,217
EAME | Business | Energy & Transportation | Reportable segments
Sales and revenue by geographic region
Revenues									4,994	4,934
EAME | Business | All Other | All Other operating segments
Sales and revenue by geographic region
Revenues									28	18
EAME | Business | Machinery, Energy & Transportation
Sales and revenue by geographic region
Revenues									10,850	11,568
EAME | Business | Financial Products Segment | Reportable segments
Sales and revenue by geographic region
Sales and revenues									408	387
EAME | Business | Financial Products
Sales and revenue by geographic region
Sales and revenues									373	361
Asia Pacific
Sales and revenue by geographic region
Sales and revenues									12,082	12,475
Asia Pacific | Machinery, Energy & Transportation | Intersegment Eliminations
Sales and revenue by geographic region
Revenues									(14)	(2)
Asia Pacific | Financial Products | Intersegment Eliminations
Sales and revenue by geographic region
Sales and revenues									(69)	(73)
Asia Pacific | Business | Construction Industries | Reportable segments
Sales and revenue by geographic region
Revenues									5,556	6,473
Asia Pacific | Business | Resource Industries | Reportable segments
Sales and revenue by geographic region
Revenues									2,812	2,667
Asia Pacific | Business | Energy & Transportation | Reportable segments
Sales and revenue by geographic region
Revenues									3,238	2,882
Asia Pacific | Business | All Other | All Other operating segments
Sales and revenue by geographic region
Revenues									67	70
Asia Pacific | Business | Machinery, Energy & Transportation
Sales and revenue by geographic region
Revenues									11,659	12,090
Asia Pacific | Business | Financial Products Segment | Reportable segments
Sales and revenue by geographic region
Sales and revenues									492	458
Asia Pacific | Business | Financial Products
Sales and revenue by geographic region
Sales and revenues									423	385
Oil and Gas [Member] | Energy & Transportation
Sales and revenue by geographic region
Sales and revenues									5,205	5,763
Power generation [Member] | Energy & Transportation
Sales and revenue by geographic region
Sales and revenues									4,474	4,334
Industrial [Member] | Energy & Transportation
Sales and revenue by geographic region
Sales and revenues									3,749	3,640
Transportation [Member] | Energy & Transportation
Sales and revenue by geographic region
Sales and revenues									$ 5,057	$ 5,095