| **Transactions with Related Parties (Tables)** | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
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| **Related Party Transactions [Abstract]**      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| Transactions with Related Parties              | We have variable amount lending agreements and other notes receivable with Caterpillar.  Under these agreements, we may borrow up to $2.45 billion from Caterpillar, and Caterpillar may borrow up to $1.66 billion from us.  The agreements are in effect for indefinite periods of time and may be changed or terminated by either party with 30 days notice.  During January of 2011, we extended a $2 billion committed credit facility to Caterpillar, which expires in February 2019.  Under this agreement, we receive a fee from Caterpillar based on amounts drawn under the credit facility and a commitment fee for the undrawn amounts under the credit facility.  Information concerning these agreements was as follows: (Millions of dollars)        2012 2011 2010Notes payable as of December 31, $208 $— $600Notes receivable as of December 31, $360 $327 $278Interest expense $4 $1 $3Interest income on Notes Receivable with Caterpillar(1) $21 $16 $73Fees on committed credit facility extended to Caterpillar(1) $41 $40 $—       (1) Included in Other revenues, net in the Consolidated Statements of Profit. We have agreements with Caterpillar to purchase certain trade receivables at a discount.  Information pertaining to these purchases was as follows: (Millions of dollars)        2012 2011 2010Purchases made $36,665 $32,068 $16,513Discounts earned $241 $212 $139Balance as of December 31, $3,114 $3,154 $1,815        |

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| - Definition
Tabular disclosure of related party transactions. Examples of related party transactions include, but are not limited to, transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners and (d) affiliates.
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No definition available.
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