Derivative Financial Instruments and Risk Management (Policies)	6 Months Ended
Jun. 30, 2012
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Risk Management Policy	Foreign Currency Exchange Rate Risk Foreign currency exchange rate movements create a degree of risk by affecting the U.S. dollar value of sales made and costs incurred in foreign currencies. Movements in foreign currency rates also affect our competitive position as these changes may affect business practices and/or pricing strategies of non-U.S.-based competitors. Additionally, we have balance sheet positions denominated in foreign currencies, thereby creating exposure to movements in exchange rates. Our Machinery and Power Systems operations purchase, manufacture and sell products in many locations around the world. As we have a diversified revenue and cost base, we manage our future foreign currency cash flow exposure on a net basis. We use foreign currency forward and option contracts to manage unmatched foreign currency cash inflow and outflow. Our objective is to minimize the risk of exchange rate movements that would reduce the U.S. dollar value of our foreign currency cash flow. Our policy allows for managing anticipated foreign currency cash flow for up to five years. We generally designate as cash flow hedges at inception of the contract any Australian dollar, Brazilian real, British pound, Canadian dollar, Chinese yuan, euro, Indian rupee, Japanese yen, Mexican peso, Singapore dollar or Swiss franc forward or option contracts that meet the requirements for hedge accounting and the maturity extends beyond the current quarter-end. Designation is performed on a specific exposure basis to support hedge accounting. The remainder of Machinery and Power Systems foreign currency contracts are undesignated, including any hedges designed to protect our competitive exposure. As of June 30, 2012, $18 million of deferred net losses, net of tax, included in equity (Accumulated other comprehensive income (loss) in the Consolidated Statement of Financial Position), are expected to be reclassified to current earnings (Other income (expense) in the Consolidated Statement of Results of Operations) over the next twelve months when earnings are affected by the hedged transactions. The actual amount recorded in Other income (expense) will vary based on exchange rates at the time the hedged transactions impact earnings. In managing foreign currency risk for our Financial Products operations, our objective is to minimize earnings volatility resulting from conversion and the remeasurement of net foreign currency balance sheet positions. Our policy allows the use of foreign currency forward and option contracts to offset the risk of currency mismatch between our receivables and debt. All such foreign currency forward and option contracts are undesignated. Interest Rate Risk Interest rate movements create a degree of risk by affecting the amount of our interest payments and the value of our fixed-rate debt. Our practice is to use interest rate derivatives to manage our exposure to interest rate changes and, in some cases, lower the cost of borrowed funds. Our Machinery and Power Systems operations generally use fixed-rate debt as a source of funding. Our objective is to minimize the cost of borrowed funds. Our policy allows us to enter into fixed-to-floating interest rate swaps and forward rate agreements to meet that objective with the intent to designate as fair value hedges at inception of the contract all fixed-to-floating interest rate swaps. Designation as a hedge of the fair value of our fixed-rate debt is performed to support hedge accounting. Financial Products operations has a match-funding policy that addresses interest rate risk by aligning the interest rate profile (fixed or floating rate) of Cat Financial’s debt portfolio with the interest rate profile of their receivables portfolio within predetermined ranges on an ongoing basis. In connection with that policy, we use interest rate derivative instruments to modify the debt structure to match assets within the receivables portfolio. This matched funding reduces the volatility of margins between interest-bearing assets and interest-bearing liabilities, regardless of which direction interest rates move. Our policy allows us to use fixed-to-floating, floating-to-fixed, and floating-to-floating interest rate swaps to meet the match-funding objective. We designate fixed-to-floating interest rate swaps as fair value hedges to protect debt against changes in fair value due to changes in the benchmark interest rate. We designate most floating-to-fixed interest rate swaps as cash flow hedges to protect against the variability of cash flows due to changes in the benchmark interest rate. As of June 30, 2012, $3 million of deferred net losses, net of tax, included in equity (Accumulated other comprehensive income (loss) in the Consolidated Statement of Financial Position), related to Financial Products floating-to-fixed interest rate swaps, are expected to be reclassified to current earnings (Interest expense of Financial Products in the Consolidated Statement of Results of Operations) over the next twelve months. The actual amount recorded in Interest expense of Financial Products will vary based on interest rates at the time the hedged transactions impact earnings. We have, at certain times, liquidated fixed-to-floating and floating-to-fixed interest rate swaps at both Machinery and Power Systems and Financial Products. The gains or losses associated with these swaps at the time of liquidation are amortized into earnings over the original term of the previously designated hedged item. In anticipation of issuing debt for the planned acquisition of Bucyrus International, Inc., we entered into interest rate swaps to manage our exposure to interest rate changes. For the three and six months ended June 30, 2011, we recognized a net loss of $124 million and $149 million, respectively, included in Other income (expense) in the Consolidated Statement of Results of Operations. These contracts were not designated as hedging instruments, and therefore, did not receive hedge accounting treatment. The contracts were liquidated in conjunction with the debt issuance in May 2011. Commodity Price Risk Commodity price movements create a degree of risk by affecting the price we must pay for certain raw material. Our policy is to use commodity forward and option contracts to manage the commodity risk and reduce the cost of purchased materials. Our Machinery and Power Systems operations purchase base and precious metals embedded in the components we purchase from suppliers. Our suppliers pass on a share of the price changes in the commodity portion of the component cost. In addition, we are subject to price changes on energy products such as natural gas and diesel fuel purchased for operational use. Our objective is to minimize volatility in the price of these commodities. Our policy allows us to enter into commodity forward and option contracts to lock in the purchase price of a portion of these commodities within a five-year horizon. All such commodity forward and option contracts are undesignated.

Foreign Currency Exchange Rate Risk

Foreign currency exchange rate movements create a degree of risk by affecting the U.S. dollar value of sales made and costs incurred in foreign currencies. Movements in foreign currency rates also affect our competitive position as these changes may affect business practices and/or pricing strategies of non-U.S.-based competitors. Additionally, we have balance sheet positions denominated in foreign currencies, thereby creating exposure to movements in exchange rates.

Our Machinery and Power Systems operations purchase, manufacture and sell products in many locations around the world. As we have a diversified revenue and cost base, we manage our future foreign currency cash flow exposure on a net basis. We use foreign currency forward and option contracts to manage unmatched foreign currency cash inflow and outflow. Our objective is to minimize the risk of exchange rate movements that would reduce the U.S. dollar value of our foreign currency cash flow. Our policy allows for managing anticipated foreign currency cash flow for up to five years.

We generally designate as cash flow hedges at inception of the contract any Australian dollar, Brazilian real, British pound, Canadian dollar, Chinese yuan, euro, Indian rupee, Japanese yen, Mexican peso, Singapore dollar or Swiss franc forward or option contracts that meet the requirements for hedge accounting and the maturity extends beyond the current quarter-end. Designation is performed on a specific exposure basis to support hedge accounting. The remainder of Machinery and Power Systems foreign currency contracts are undesignated, including any hedges designed to protect our competitive exposure.

As of June 30, 2012, $18 million of deferred net losses, net of tax, included in equity (Accumulated other comprehensive income (loss) in the Consolidated Statement of Financial Position), are expected to be reclassified to current earnings (Other income (expense) in the Consolidated Statement of Results of Operations) over the next twelve months when earnings are affected by the hedged transactions. The actual amount recorded in Other income (expense) will vary based on exchange rates at the time the hedged transactions impact earnings.

In managing foreign currency risk for our Financial Products operations, our objective is to minimize earnings volatility resulting from conversion and the remeasurement of net foreign currency balance sheet positions. Our policy allows the use of foreign currency forward and option contracts to offset the risk of currency mismatch between our receivables and debt. All such foreign currency forward and option contracts are undesignated.

Interest Rate Risk

Interest rate movements create a degree of risk by affecting the amount of our interest payments and the value of our fixed-rate debt. Our practice is to use interest rate derivatives to manage our exposure to interest rate changes and, in some cases, lower the cost of borrowed funds.

Our Machinery and Power Systems operations generally use fixed-rate debt as a source of funding. Our objective is to minimize the cost of borrowed funds. Our policy allows us to enter into fixed-to-floating interest rate swaps and forward rate agreements to meet that objective with the intent to designate as fair value hedges at inception of the contract all fixed-to-floating interest rate swaps. Designation as a hedge of the fair value of our fixed-rate debt is performed to support hedge accounting.

Financial Products operations has a match-funding policy that addresses interest rate risk by aligning the interest rate profile (fixed or floating rate) of Cat Financial’s debt portfolio with the interest rate profile of their receivables portfolio within predetermined ranges on an ongoing basis. In connection with that policy, we use interest rate derivative instruments to modify the debt structure to match assets within the receivables portfolio. This matched funding reduces the volatility of margins between interest-bearing assets and interest-bearing liabilities, regardless of which direction interest rates move.

Our policy allows us to use fixed-to-floating, floating-to-fixed, and floating-to-floating interest rate swaps to meet the match-funding objective. We designate fixed-to-floating interest rate swaps as fair value hedges to protect debt against changes in fair value due to changes in the benchmark interest rate. We designate most floating-to-fixed interest rate swaps as cash flow hedges to protect against the variability of cash flows due to changes in the benchmark interest rate.

As of June 30, 2012, $3 million of deferred net losses, net of tax, included in equity (Accumulated other comprehensive income (loss) in the Consolidated Statement of Financial Position), related to Financial Products floating-to-fixed interest rate swaps, are expected to be reclassified to current earnings (Interest expense of Financial Products in the Consolidated Statement of Results of Operations) over the next twelve months. The actual amount recorded in Interest expense of Financial Products will vary based on interest rates at the time the hedged transactions impact earnings.

We have, at certain times, liquidated fixed-to-floating and floating-to-fixed interest rate swaps at both Machinery and Power Systems and Financial Products. The gains or losses associated with these swaps at the time of liquidation are amortized into earnings over the original term of the previously designated hedged item.

In anticipation of issuing debt for the planned acquisition of Bucyrus International, Inc., we entered into interest rate swaps to manage our exposure to interest rate changes. For the three and six months ended June 30, 2011, we recognized a net loss of $124 million and $149 million, respectively, included in Other income (expense) in the Consolidated Statement of Results of Operations. These contracts were not designated as hedging instruments, and therefore, did not receive hedge accounting treatment. The contracts were liquidated in conjunction with the debt issuance in May 2011.

Commodity Price Risk

Commodity price movements create a degree of risk by affecting the price we must pay for certain raw material. Our policy is to use commodity forward and option contracts to manage the commodity risk and reduce the cost of purchased materials.

Our Machinery and Power Systems operations purchase base and precious metals embedded in the components we purchase from suppliers. Our suppliers pass on a share of the price changes in the commodity portion of the component cost. In addition, we are subject to price changes on energy products such as natural gas and diesel fuel purchased for operational use.

Our objective is to minimize volatility in the price of these commodities. Our policy allows us to enter into commodity forward and option contracts to lock in the purchase price of a portion of these commodities within a five-year horizon. All such commodity forward and option contracts are undesignated.