2.2.0.25falsefalse4010 - Disclosure - Operations and summary of significant accounting policies (Details)truefalseIn Millions, unless otherwise specifiedfalse1falsefalseUSDfalsefalse1/1/2010 - 12/31/2010
USD ($)
USD ($) / shares
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USD ($)
USD ($) / shares
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USD ($)
USD ($) / shares
$D2008http://www.sec.gov/CIK0000018230duration2008-01-01T00:00:002008-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDPerShareDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2true0cat_OperationsAndSummaryOfSignificantAccountingPoliciesDisclosureAbstractcatfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalse3false0cat_EquityMethodInvestmentOwnershipPrecentageLowEndOfRangecatfalsenadurationThe minimum ownership percentage of investments in companies, except where significant influence is exercised, to 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available.falsefalse5false0cat_EquityMethodInvestmentOwnershipPrecentageSignificantInfluencecatfalsenadurationThe ownership percentage of investments in companies below which the entity must exercise significant influence in order to...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truetruefalse0.200.20falsefalsefalsefalsefalse2falsetruefalse00falsefalsefalsefalsefalse3falsetruefalse00falsefalsefalsefalsefalseOtherus-types:percentItemTypepureThe ownership percentage of investments in companies below which the entity must exercise significant influence in order to be accounted for under the equity method.No authoritative reference available.falsefalse6false0us-gaap_SecurityDepositus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse232000000232falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of an 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standard invoice terms not more than one year.No authoritative reference available.falsefalse10false0us-gaap_PercentageOfLIFOInventoryus-gaaptruenainstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truetruefalse0.700.70falsefalsefalsefalsefalse2truetruefalse0.700.70falsefalsefalsefalsefalse3truetruefalse0.700.70falsefalsefalsefalsefalseOtherus-types:percentItemTypepureThe percentage of LIFO (last in first out) inventory to total inventory as of the balance sheet date if other than 100 percent.No authoritative reference available.falsefalse11false0us-gaap_InventoryLIFOReserveus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse25750000002575falsefalsefalsefalsefalse2truefalsefalse30220000003022falsefalsefalsefalsefalse3truefalsefalse32160000003216falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryReflects the difference between (a) inventory at the lower of LIFO cost or market and (b) inventory at replacement cost or at the lower of some acceptable inventory accounting method (such as FIFO or average cost), or market. If material, reflects an excess of replacement or current cost over stated LIFO value parenthetically on the balance sheet or in a note to the financial statements.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 6
-Subparagraph c
-Article 5
falsefalse12false0us-gaap_OperatingLeasesIncomeStatementDepreciationExpenseOnPropertySubjectToOrHeldForLeaseus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse690000000690falsefalsefalsefalsefalse2truefalsefalse713000000713falsefalsefalsefalsefalse3truefalsefalse724000000724falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe total depreciation charge recorded for property subject to or held for lease.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 5
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 28
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 5
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