Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Y Segment	Mar. 31, 2011	Dec. 31, 2011
Reportable Segments
Number of operating segments led by Group Presidents	3
Number of operating segment led by Group president responsible for corporate services	1
Number of operating segments	5
Number of reportable segments	4
Useful life of goodwill (in years)	20
External sales and revenues	$ 15,981	$ 12,949
Depreciation and amortization	661	575
Segment profit (loss)	2,323	1,833
Segment assets	83,908		81,446
Reportable segments
Reportable Segments
External sales and revenues	15,588	12,418
Inter-segment sales and revenues	1,133	975
Total sales and revenues	16,721	13,393
Depreciation and amortization	606	503
Segment profit (loss)	2,801	2,176
Segment assets	63,700		60,729
Capital expenditures	735	400
Machinery and Power Systems
Reportable Segments
External sales and revenues	15,288	12,277
Depreciation and amortization	482	395
Segment assets	56,413		54,679
Machinery and Power Systems | Reportable segments
Reportable Segments
External sales and revenues	14,827	11,688
Inter-segment sales and revenues	1,133	975
Total sales and revenues	15,960	12,663
Depreciation and amortization	432	327
Segment profit (loss)	2,596	2,040
Segment assets	31,242		28,982
Capital expenditures	392	220
Construction Industries | Reportable segments
Reportable Segments
External sales and revenues	5,062	4,471
Inter-segment sales and revenues	130	147
Total sales and revenues	5,192	4,618
Depreciation and amortization	131	120
Segment profit (loss)	616	544
Segment assets	8,899		7,942
Capital expenditures	131	79
Resource Industries | Reportable segments
Reportable Segments
External sales and revenues	4,778	2,768
Inter-segment sales and revenues	328	274
Total sales and revenues	5,106	3,042
Depreciation and amortization	163	71
Segment profit (loss)	1,168	796
Segment assets	13,050		12,292
Capital expenditures	132	56
Power Systems | Reportable segments
Reportable Segments
External sales and revenues	4,987	4,449
Inter-segment sales and revenues	675	554
Total sales and revenues	5,662	5,003
Depreciation and amortization	138	136
Segment profit (loss)	812	700
Segment assets	9,293		8,748
Capital expenditures	129	85
Financial Products Segment | Reportable segments
Reportable Segments
External sales and revenues	761	730
Total sales and revenues	761	730
Depreciation and amortization	174	176
Segment profit (loss)	205	136
Segment assets	32,458		31,747
Capital expenditures	$ 343	$ 180