Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 group_presidents segments	Sep. 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	$ 16,445	$ 15,716	$ 49,800	$ 42,895
Depreciation and amortization	720	658	2,070	1,832
Segment profit (loss)	2,596	1,759	7,535	5,193
Segment assets	90,541		90,541		81,446
Reportable segments
Reportable Segments
External sales and revenues	16,211	15,331	48,804	41,578
Inter-segment sales and revenues	952	1,052	3,216	2,976
Total sales and revenues	17,163	16,383	52,020	44,554
Depreciation and amortization	659	601	1,896	1,613
Segment profit (loss)	2,705	2,180	8,790	6,542
Segment assets	69,030		69,030		60,729
Capital expenditures	1,152	983	3,042	2,117
Machinery and Power Systems
Reportable Segments
External sales and revenues	15,739	15,023	47,711	40,835
Depreciation and amortization	535	477	1,523	1,287
Segment assets	60,223		60,223		54,679
Machinery and Power Systems | Reportable segments
Reportable Segments
External sales and revenues	15,435	14,574	46,503	39,327
Inter-segment sales and revenues	952	1,052	3,216	2,976
Total sales and revenues	16,387	15,626	49,719	42,303
Depreciation and amortization	480	424	1,366	1,078
Segment profit (loss)	2,515	2,035	8,207	6,089
Segment assets	33,368		33,368		28,982
Capital expenditures	720	672	1,810	1,287
Construction Industries | Reportable segments
Reportable Segments
External sales and revenues	4,904	4,900	15,306	14,312
Inter-segment sales and revenues	102	162	355	433
Total sales and revenues	5,006	5,062	15,661	14,745
Depreciation and amortization	144	136	414	382
Segment profit (loss)	459	496	1,763	1,522
Segment assets	9,681		9,681		7,942
Capital expenditures	247	234	597	471
Resource Industries | Reportable segments
Reportable Segments
External sales and revenues	5,214	4,599	15,382	10,573
Inter-segment sales and revenues	253	290	909	848
Total sales and revenues	5,467	4,889	16,291	11,421
Depreciation and amortization	179	155	510	298
Segment profit (loss)	1,113	745	3,707	2,337
Segment assets	13,949		13,949		12,292
Capital expenditures	229	159	603	320
Power Systems | Reportable segments
Reportable Segments
External sales and revenues	5,317	5,075	15,815	14,442
Inter-segment sales and revenues	597	600	1,952	1,695
Total sales and revenues	5,914	5,675	17,767	16,137
Depreciation and amortization	157	133	442	398
Segment profit (loss)	943	794	2,737	2,230
Segment assets	9,738		9,738		8,748
Capital expenditures	244	279	610	496
Financial Products Segment | Reportable segments
Reportable Segments
External sales and revenues	776	757	2,301	2,251
Inter-segment sales and revenues	0	0	0	0
Total sales and revenues	776	757	2,301	2,251
Depreciation and amortization	179	177	530	535
Segment profit (loss)	190	145	583	453
Segment assets	35,662		35,662		31,747
Capital expenditures	$ 432	$ 311	$ 1,232	$ 830