Investments in Unconsolidated Affiliated Companies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Feb. 28, 2015
Results of Operations of unconsolidated affiliated companies:
Sales	$ 163	$ 390
Cost of sales	125	301
Gross profit	38	89
Profit (loss)	4	(14)
Assets:
Current assets	511		716
Property, plant and equipment - net	173		653
Other assets	166		557
Assets	850		1,926
Liabilities:
Current liabilities	290		518
Long-term debt due after one year	148		867
Other liabilities	10		215
Liabilities	448		1,600
Equity	402		326
Caterpillar's investments in unconsolidated affiliated companies:
Investments in equity method companies	196us-gaap_EquityMethodInvestments		248us-gaap_EquityMethodInvestments
Plus: Investments in cost method companies	34us-gaap_CostMethodInvestments		9us-gaap_CostMethodInvestments
Total investments in unconsolidated affiliated companies	$ 230		$ 257
Third party logistics business, investment
Schedule of Equity Method Investments [Line Items]
Percentage of equity interest sold				35.00%

Percent of the reporting entity's equity method investment which has been sold.

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This item represents the disclosure of summarized financial information for unconsolidated subsidiaries and 50 percent-or-less owned entities accounted for using the equity method of accounting. If investments in common stock of corporate joint ventures or other investments accounted for under the equity method are, in the aggregate, material in relation to the financial position or results of operations of an investor, it may be necessary to present summarized information as to assets of the investee, or group of investments for which combined disclosure is appropriate, either by individual financial statement caption or in groups, as appropriate. This element represents other assets.

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Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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The amount of assets reported by an equity method investment of the entity.

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The amount of the cost of sales reported by an equity method investment of the entity.

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The amount of current assets reported by an equity method investment of the entity.

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The amount of current liabilities reported by an equity method investment of the entity.

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Amount of equity, excluding noncontrolling interest, attributable to the equity method investment of the entity.

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The amount of gross profit (loss) reported by an equity method investment of the entity.

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The amount of liabilities reported by an equity method investment of the entity.

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The amount of net income (loss) reported by an equity method investment of the entity.

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The amount of revenue from sale of goods and services reduced by sales returns, allowances, and discounts reported by an equity method investment of the entity.

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Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

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