|**Guarantees**            | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
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|**Guarantees [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
|Guarantees                | GuaranteesWe provide loan guarantees to third-party lenders for financing associated with machinery purchased by customers.  These guarantees have varying terms and are secured by the machinery being financed.  In addition, we participate in standby letters of credit issued to third parties on behalf of our customers.  These standby letters of credit have varying terms and beneficiaries and are secured by customer assets.We have provided a limited indemnity to a third-party bank resulting from the assignment of certain leases to that bank.  The indemnity is for the possibility that the insurers of these leases would become insolvent.  The indemnity expires December 15, 2012 and is unsecured.No loss has been experienced or is anticipated under any of these guarantees.  AtSeptember 30, 2012andDecember 31, 2011, the related liability was$3 millionand$2 million, respectively.  The maximum potential amount of future payments (undiscounted and without reduction for any amounts that may possibly be recovered under recourse or collateralized provisions) we could be required to make under the guarantees was as follows:(Millions of dollars)September 30, 2012December 31, 2011Customer guarantees$156$159Limited indemnity111Total guarantees$157$170We provide guarantees to repurchase certain loans of Caterpillar dealers from a special purpose corporation (SPC) that qualifies as a VIE (see Note 1 for additional information regarding the accounting guidance on the consolidation of VIEs).  The purpose of the SPC is to provide short-term working capital loans to Caterpillar dealers.  This SPC issues commercial paper and uses the proceeds to fund its loan program.  We have a loan purchase agreement with the SPC that obligates us to purchase certain loans that are not paid at maturity.  We receive a fee for providing this guarantee, which provides a source of liquidity for the SPC.  We are the primary beneficiary of the SPC as our guarantees result in us having both the power to direct the activities that most significantly impact the SPC's economic performance and the obligation to absorb losses, and therefore we have consolidated the financial statements of the SPC.  As ofSeptember 30, 2012andDecember 31, 2011, the SPC’s assets of$940 millionand$586 million, respectively, are primarily comprised of loans to dealers, which are included in Retail notes receivable in the Consolidated Statements of Financial Position, and the SPC's liabilities of$940 millionand$586 million, respectively, are primarily comprised of commercial paper, which is included in Short-term borrowings in the Consolidated Statements of Financial Position.  The assets of the SPC are not available to pay our creditors.  We may be obligated to perform under the guarantee if the SPC experiences losses.  No loss has been experienced or is anticipated under this loan purchase agreement.
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|(Millions of dollars)     | September 30, 2012                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Customer guarantees       | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
|Limited indemnity         | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
|Total guarantees          | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
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