Cat Financial Financing Activities (Details Non-accrual) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Receivables [Abstract]
Period after which Collection of Future Income is Considered as Not Probable	120 days
Dealer
Financing Receivable, Nonaccrual
Interest income recognized for finance receivables on non-accrual status	$ 0	$ 0
Recorded investment, non-accrual finance receivables	73		$ 78
Customer
Financing Receivable, Nonaccrual
Interest income recognized for finance receivables on non-accrual status	1	$ 3
Finance Receivables \| Dealer
Financing Receivable, Nonaccrual
Financing Receivable, 91 days past due and still accruing	0		0
Finance Receivables \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	186		184
Amortized Cost, Non-accrual Without an Allowance	20		26
Financing Receivable, 91 days past due and still accruing	30		36
Finance Receivables \| North America \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	43		47
Amortized Cost, Non-accrual Without an Allowance	6		9
Financing Receivable, 91 days past due and still accruing	13		12
Finance Receivables \| EAME \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	20		18
Amortized Cost, Non-accrual Without an Allowance	1		1
Financing Receivable, 91 days past due and still accruing	2		2
Finance Receivables \| Asia/Pacific \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	13		19
Amortized Cost, Non-accrual Without an Allowance	0		0
Financing Receivable, 91 days past due and still accruing	13		7
Finance Receivables \| Mining \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	28		8
Amortized Cost, Non-accrual Without an Allowance	1		1
Financing Receivable, 91 days past due and still accruing	1		14
Finance Receivables \| Latin America \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	51		52
Amortized Cost, Non-accrual Without an Allowance	0		4
Financing Receivable, 91 days past due and still accruing	1		1
Finance Receivables \| Caterpillar Power Finance \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	31		40
Amortized Cost, Non-accrual Without an Allowance	12		11
Financing Receivable, 91 days past due and still accruing	$ 0		$ 0

Financing Receivables that are 91 days or more past due and still accruing.

No definition available.

Name:	cat_FinancingReceivable91dayspastdueandstillaccruing
Namespace Prefix:	cat_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the period after which collection of future income is considered as not probable.

+ References

No definition available.

+ Details

Name:	cat_PeriodAfterWhichCollectionOfFutureIncomeIsConsideredAsNotProbable
Namespace Prefix:	cat_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of interest income on financing receivable on nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447

+ Details

Name:	us-gaap_FinancingReceivableNonaccrualInterestIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of financing receivable on nonaccrual status with no allowance for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableNonaccrualStatusLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of financing receivable on nonaccrual status.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (3)

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (2)

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

+ References

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedNonperformingNonaccrualOfInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=cat_CustomerMember
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- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cat_FinanceReceivableMember
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- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=srt_NorthAmericaMember
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- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_EMEAMember
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- Details

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- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cat_MiningMember
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- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=srt_LatinAmericaMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cat_CaterpillarPowerFinanceMember
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