Investments in Unconsolidated Affiliated Companies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Segment Y M D	Sep. 30, 2010	Dec. 31, 2010
Investments in Unconsolidated Affiliated Companies
General reporting period lag time, or less, for combining financial information of unconsolidated affiliated companies (in months)			3
Results of Operations of unconsolidated affiliated companies:
Sales	$ 302	$ 216	$ 741	$ 580
Cost of sales	257	171	616	445
Gross profit	45	45	125	135
Profit (loss)	(12)	(10)	(46)	(12)
Assets:
Current assets	310		310		414
Property, plant and equipment - net	172		172		196
Other assets	7		7		39
Assets	489		489		649
Liabilities:
Current liabilities	202		202		274
Long-term debt due after one year	74		74		72
Other liabilities	12		12		40
Liabilities	288		288		386
Equity	201		201		263
Caterpillar's investments in unconsolidated affiliated companies:
Investments in equity method companies	99		99		135
Plus: Investments in cost method companies	22		22		29
Total investments in unconsolidated affiliated companies	$ 121		$ 121		$ 164

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 liabilities 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 long-term debt.

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