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

Name:	us-gaap_FinancingReceivableNonaccrualNoAllowance
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

- References

No definition available.

+ Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=cat_DealerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=cat_CustomerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cat_FinanceReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=srt_NorthAmericaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_EMEAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=srt_AsiaPacificMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cat_MiningMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cat_CaterpillarPowerFinanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Cat Financial Financing Activities (Details Non-accrual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
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	$ 0	$ 0
Customer
Financing Receivable, Nonaccrual
Interest income recognized for finance receivables on non-accrual status	1	$ 2	9	$ 8
Finance Receivables \| Dealer
Financing Receivable, Nonaccrual
Financing Receivable, 91 days past due and still accruing	0		0		$ 0
Finance Receivables \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	251		251		466
Amortized Cost, Non-accrual Without an Allowance	9		9		20
Financing Receivable, 91 days past due and still accruing	31		31		49
Finance Receivables \| North America \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	54		54		86
Amortized Cost, Non-accrual Without an Allowance	7		7		1
Financing Receivable, 91 days past due and still accruing	17		17		34
Finance Receivables \| EAME \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	50		50		113
Amortized Cost, Non-accrual Without an Allowance	1		1		1
Financing Receivable, 91 days past due and still accruing	4		4		1
Finance Receivables \| Asia/Pacific \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	21		21		13
Amortized Cost, Non-accrual Without an Allowance	0		0		0
Financing Receivable, 91 days past due and still accruing	9		9		13
Finance Receivables \| Mining \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	9		9		21
Amortized Cost, Non-accrual Without an Allowance	1		1		1
Financing Receivable, 91 days past due and still accruing	0		0		0
Finance Receivables \| Latin America \| Dealer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	78		78		81
Finance Receivables \| Latin America \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	42		42		63
Amortized Cost, Non-accrual Without an Allowance	0		0		0
Financing Receivable, 91 days past due and still accruing	1		1		1
Finance Receivables \| Caterpillar Power Finance \| Customer
Financing Receivable, Nonaccrual
Amortized Cost, Non-accrual With an Allowance	75		75		170
Amortized Cost, Non-accrual Without an Allowance	0		0		17
Financing Receivable, 91 days past due and still accruing	$ 0		$ 0		$ 0