Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Reportable Segments
Number of group presidents			5
Number of operating segments led by Group Presidents			3
Number of operating segment led by Group president responsible for corporate services			1
Number of smaller operating segments led by Group President			1
Number of operating segments			5
Number of reportable segments			4
External sales and revenues	$ 17,374	$ 14,230	$ 33,355	$ 27,179
Depreciation and amortization	689	599	1,350	1,174
Segment profit (loss)	2,616	1,601	4,939	3,434
Segment assets	88,838		88,838		81,446
Reportable segments
Reportable Segments
External sales and revenues	17,005	13,829	32,593	26,247
Inter-segment sales and revenues	1,131	949	2,264	1,924
Total sales and revenues	18,136	14,778	34,857	28,171
Depreciation and amortization	631	509	1,237	1,012
Segment profit (loss)	3,284	2,186	6,085	4,362
Segment assets	67,217		67,217		60,729
Capital expenditures	1,155	734	1,890	1,134
Machinery and Power Systems
Reportable Segments
External sales and revenues	16,684	13,535	31,972	25,812
Depreciation and amortization	506	415	988	810
Segment assets	59,209		59,209		54,679
Machinery and Power Systems | Reportable segments
Reportable Segments
External sales and revenues	16,241	13,065	31,068	24,753
Inter-segment sales and revenues	1,131	949	2,264	1,924
Total sales and revenues	17,372	14,014	33,332	26,677
Depreciation and amortization	454	327	886	654
Segment profit (loss)	3,096	2,014	5,692	4,054
Segment assets	32,766		32,766		28,982
Capital expenditures	698	395	1,090	615
Construction Industries | Reportable segments
Reportable Segments
External sales and revenues	5,340	4,941	10,402	9,412
Inter-segment sales and revenues	123	124	253	271
Total sales and revenues	5,463	5,065	10,655	9,683
Depreciation and amortization	139	126	270	246
Segment profit (loss)	688	482	1,304	1,026
Segment assets	9,771		9,771		7,942
Capital expenditures	219	158	350	237
Resource Industries | Reportable segments
Reportable Segments
External sales and revenues	5,390	3,206	10,168	5,974
Inter-segment sales and revenues	328	284	656	558
Total sales and revenues	5,718	3,490	10,824	6,532
Depreciation and amortization	168	72	331	143
Segment profit (loss)	1,426	796	2,594	1,592
Segment assets	13,499		13,499		12,292
Capital expenditures	242	105	374	161
Power Systems | Reportable segments
Reportable Segments
External sales and revenues	5,511	4,918	10,498	9,367
Inter-segment sales and revenues	680	541	1,355	1,095
Total sales and revenues	6,191	5,459	11,853	10,462
Depreciation and amortization	147	129	285	265
Segment profit (loss)	982	736	1,794	1,436
Segment assets	9,496		9,496		8,748
Capital expenditures	237	132	366	217
Financial Products Segment | Reportable segments
Reportable Segments
External sales and revenues	764	764	1,525	1,494
Inter-segment sales and revenues	0	0	0	0
Total sales and revenues	764	764	1,525	1,494
Depreciation and amortization	177	182	351	358
Segment profit (loss)	188	172	393	308
Segment assets	34,451		34,451		31,747
Capital expenditures	$ 457	$ 339	$ 800	$ 519