Guarantees and Product Warranty (Details 2) (USD $) In Millions	6 Months Ended	12 Months Ended
Jun. 30, 2011	Dec. 31, 2010
Movement in Standard Product Warranty Accrual
Warranty liability, beginning balance	$ 1,035	$ 1,049
Payments	(436)	(855)
Provisions	521	841
Warranty liability, ending balance	$ 1,120	$ 1,035

Represents the aggregate increase in the liability for accruals related to provisions for standard product warranties.

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Namespace Prefix:	cat
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ Details

Name:	us-gaap_MovementInStandardProductWarrantyAccrualRollForward
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
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- Definition

Amount as of the balance sheet date of the aggregate standard product warranty liability. Does not include the balance for the extended product warranty liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 45
-Paragraph 14
-Subparagraph b

+ Details

Name:	us-gaap_StandardProductWarrantyAccrual
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the aggregate decrease in the liability for payments made (in cash or in kind) to satisfy claims under the terms of the standard product warranty. Does not include any increase (decrease) in the liability for payments related to extended product warranties

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 45
-Paragraph 14
-Subparagraph b

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration