Cat Financial Financing Activities (Details 7) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2009	Dec. 31, 2008
Cat Financial Financing Activities
Annual servicing fee percentage (as a percent)	0.50%	0.50%
Consolidated expenses related to sale of trade receivables	$ 4	$ 10
Outstanding principal balance of the sold trade receivables		240
Remaining interest in trade receivables		1,432
Cash flows from sale of trade receivables:
Cash proceeds from sales of receivables to the conduits	887	1,510
Servicing fees received	1	1
Cash flows received on the interests that continue to be held	$ 7,548	$ 11,270

This element represents interests that continue to be held by the transferor related to an asset-backed financing arrangement or similar transfer accounted for as a sale when the transferor has continuing involvement with the transferred financial assets.

Name:	cat_AccountsReceivableSoldRemainingInterestInPoolOfReceivables
Namespace Prefix:	cat
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cash flows on the interests that continue to be held by the transferor related to an asset-backed financing arrangement or similar transfer accounted for as a sale when the transferor has continuing involvement with the transferred financial assets.

+ Details

Name:	cat_CashFlowsBetweenTransfereeAndTransferorTradeReceivablesCashFlowsOnRetainedInterest
Namespace Prefix:	cat
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Cash proceeds from collections reinvested in revolving-period transfers related to an asset-backed financing arrangement or similar transfer accounted for as a sale when the transferor has continuing involvement with the transferred financial assets.

+ Details

Name:	cat_CashFlowsBetweenTransfereeAndTransferorTradeReceivablesProceedsCollectionsReinvested
Namespace Prefix:	cat
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	cat_FinancialFinancingActivitiesDisclosureAbstract
Namespace Prefix:	cat
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the outstanding principal balance of sold trade receivables as of the balance sheet date.

+ Details

Name:	cat_OutstandingPrincipalBalanceOfSoldTradeReceivables
Namespace Prefix:	cat
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the expenses on transfer of financial asset for securitization or asset backed financing arrangement.

+ Details

Name:	cat_SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleExpensesOnSale
Namespace Prefix:	cat
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents the percentage servicing fee received by the transferor for servicing responsibilities retained.

+ Details

Name:	cat_ServicingFeePercentageOfRemainingReceivables
Namespace Prefix:	cat
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the servicing fees received from the transferee for the servicing responsibilities retained.

+ Details

Name:	cat_ServicingFeesReceivedOnTradeReceivablesSold
Namespace Prefix:	cat
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_ProceedsFromSaleAndCollectionOfReceivablesAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration