Financing Activities (Details 3) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses
Balance at beginning of period	$ 369	$ 363
Receivables written off	(92)	(210)
Recoveries on receivables previously written off	36	52
Provision for credit losses	91	170
Adjustment due to sale of receivables	(1)	(3)
Foreign currency translation adjustment	1	(3)
Balance at end of period	404	369
Allowance for Credit Losses
Individually evaluated for impairment	75	56
Collectively evaluated for impairment	329	313
Allowance, Ending Balance	404	369
Recorded Investment in Finance Receivables
Individually evaluated for impairment	730	575
Collectively evaluated for impairment	26,786	24,550
Recorded Investment in Finance Receivables, Ending Balance	27,516	25,125
Customer
Financing Receivable, Allowance for Credit Losses
Balance at beginning of period	360	357
Receivables written off	(92)	(210)
Recoveries on receivables previously written off	36	52
Provision for credit losses	90	167
Adjustment due to sale of receivables	(1)	(3)
Foreign currency translation adjustment	1	(3)
Balance at end of period	394	360
Allowance for Credit Losses
Individually evaluated for impairment	75	56
Collectively evaluated for impairment	319	304
Allowance, Ending Balance	394	360
Recorded Investment in Finance Receivables
Individually evaluated for impairment	730	575
Collectively evaluated for impairment	18,774	17,423
Recorded Investment in Finance Receivables, Ending Balance	19,504	17,998
Dealer
Financing Receivable, Allowance for Credit Losses
Balance at beginning of period	6	5
Receivables written off	0	0
Recoveries on receivables previously written off	0	0
Provision for credit losses	1	1
Adjustment due to sale of receivables	0	0
Foreign currency translation adjustment	0	0
Balance at end of period	7	6
Allowance for Credit Losses
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	7	6
Allowance, Ending Balance	7	6
Recorded Investment in Finance Receivables
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	5,062	3,973
Recorded Investment in Finance Receivables, Ending Balance	5,062	3,973
Caterpillar Purchased Receivables
Financing Receivable, Allowance for Credit Losses
Balance at beginning of period	3	1
Receivables written off	0	0
Recoveries on receivables previously written off	0	0
Provision for credit losses	0	2
Adjustment due to sale of receivables	0	0
Foreign currency translation adjustment	0	0
Balance at end of period	3	3
Allowance for Credit Losses
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	3	3
Allowance, Ending Balance	3	3
Recorded Investment in Finance Receivables
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	2,950	3,154
Recorded Investment in Finance Receivables, Ending Balance	$ 2,950	$ 3,154