Segment Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) group_presidents segments dealers	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information
Number of group presidents | group_presidents			5
Number of operating segments | segments			6
Useful life to amortize goodwill for segment assets			20 years
Reportable Segments
Total sales and revenues	$ 14,011	$ 11,331	$ 26,870	$ 21,153
Depreciation and amortization	686	720	1,367	1,430
Consolidated profit before taxes	2,186	1,159	4,320	1,448
Segment assets	78,987		78,987		$ 76,962
Capital expenditures	771	615	1,528	1,124
Revenues earned from Machinery, Energy & Transportation	118	102	$ 223	188
All Other operating segments
Segment Reporting Information
Number of group presidents | group_presidents			1
Number of smaller operating segments led by Group President | group_presidents			2
Number of wholly-owned dealers involved in segment reallocation | dealers			1
Reportable Segments
Total sales and revenues		33		70
Depreciation and amortization	58	56	$ 115	110
Consolidated profit before taxes	23	(19)	80	(33)
Segment assets	1,278		1,278		1,312
Capital expenditures	27	25	38	45
Reportable Segments Including Intersegment Eliminations
Reportable Segments
Total sales and revenues	15,251	12,339	$ 29,249	23,096
Reportable Segments
Segment Reporting Information
Number of operating segments led by Group Presidents | segments			3
Number of operating segments led by Group President responsible for corporate services | segments			1
Reportable Segments
Number of reportable segments | segments			4
Total sales and revenues	14,111	11,406	$ 27,047	21,283
Depreciation and amortization	574	596	1,140	1,191
Consolidated profit before taxes	2,711	1,884	5,221	3,406
Segment assets	55,321		55,321		53,698
Capital expenditures	774	597	1,362	1,026
Intersegment sales and revenues
Reportable Segments
Total sales and revenues	1,140	933	2,202	1,813
Machinery, Energy & Transportation | Reportable Segments Including Intersegment Eliminations
Reportable Segments
Total sales and revenues	14,422	11,563	27,627	21,560
Machinery, Energy & Transportation | Reportable Segments
Reportable Segments
Total sales and revenues	13,282	10,630	25,425	19,747
Depreciation and amortization	362	392	725	779
Consolidated profit before taxes	2,577	1,693	4,946	3,032
Segment assets	19,413		19,413		18,805
Capital expenditures	241	158	468	316
Machinery, Energy & Transportation | Intersegment sales and revenues
Reportable Segments
Total sales and revenues	1,140	933	2,202	1,813
Construction Industries | Reportable Segments Including Intersegment Eliminations
Reportable Segments
Total sales and revenues	6,172	4,959	11,849	9,059
Construction Industries | Reportable Segments
Reportable Segments
Total sales and revenues	6,137	4,930	11,796	9,021
Depreciation and amortization	90	100	179	202
Consolidated profit before taxes	1,154	900	2,271	1,534
Segment assets	4,915		4,915		4,838
Capital expenditures	62	36	104	57
Construction Industries | Intersegment sales and revenues
Reportable Segments
Total sales and revenues	35	29	53	38
Resource Industries | Reportable Segments Including Intersegment Eliminations
Reportable Segments
Total sales and revenues	2,526	1,836	4,835	3,597
Resource Industries | Reportable Segments
Reportable Segments
Total sales and revenues	2,431	1,759	4,639	3,429
Depreciation and amortization	115	130	231	257
Consolidated profit before taxes	411	99	789	259
Segment assets	6,410		6,410		6,403
Capital expenditures	39	31	62	52
Resource Industries | Intersegment sales and revenues
Reportable Segments
Total sales and revenues	95	77	196	168
Energy & Transportation | Reportable Segments Including Intersegment Eliminations
Reportable Segments
Total sales and revenues	5,724	4,768	10,943	8,904
Energy & Transportation | Reportable Segments
Reportable Segments
Total sales and revenues	4,714	3,941	8,990	7,297
Depreciation and amortization	157	162	315	320
Consolidated profit before taxes	1,012	694	1,886	1,239
Segment assets	8,088		8,088		7,564
Capital expenditures	140	91	302	207
Energy & Transportation | Intersegment sales and revenues
Reportable Segments
Total sales and revenues	1,010	827	1,953	1,607
Financial Products Segment | Reportable Segments Including Intersegment Eliminations
Reportable Segments
Total sales and revenues	829	776	1,622	1,536
Financial Products Segment | Reportable Segments
Reportable Segments
Total sales and revenues	829	776	1,622	1,536
Depreciation and amortization	212	204	415	412
Consolidated profit before taxes	134	191	275	374
Segment assets	35,908		35,908		$ 34,893
Capital expenditures	533	439	894	710
Financial Products Segment | Intersegment sales and revenues
Reportable Segments
Total sales and revenues	$ 0	$ 0	$ 0	$ 0