v3.24.2

Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Interest rate derivative portfolio	$ 4.6
Notional amount of interest-rate contracts	$ 591.6
Interest-rate contracts maturity period	9 years 8 months 12 days
Notional maturities for interest-rate contracts remainder of 2024	$ 0.0
Notional maturities for interest-rate contracts 2025	80.0
Notional maturities for interest-rate contracts 2026	30.0
Notional maturities for interest-rate contracts 2027	86.1
Notional maturities for interest-rate contracts 2028	8.5
Notional maturities for interest-rate contracts thereafter	$ 387.0
Maximum length of time for which company is hedging its exposure to the variability in future cash flows	9 years 8 months 12 days
Accumulated net gain on interest rate contracts included in AOCI expected to be reclassified to interest expense in the following 12 months	$ 8.0
Cumulative basis adjustments on discontinued hedge relationships	$ (6.4)	$ (10.3)

Notional amount of interest rate derivatives maturing in after year five.

+ References

No definition available.

+ Details

Name:	pcar_NotionalAmountOfInterestRateDerivativesMaturingInAfterYearFive
Namespace Prefix:	pcar_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Notional maturities for all interest-rate contracts for the remainder of the fiscal year.

+ References

No definition available.

+ Details

Name:	pcar_NotionalAmountOfInterestRateDerivativesMaturingInRemainderOfFiscalYear
Namespace Prefix:	pcar_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Notional maturities for all interest-rate contracts during fiscal year five.

+ References

No definition available.

+ Details

Name:	pcar_NotionalAmountOfInterestRateDerivativesMaturingInYearFive
Namespace Prefix:	pcar_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Notional maturities for all interest-rate contracts during fiscal year four.

+ References

No definition available.

+ Details

Name:	pcar_NotionalAmountOfInterestRateDerivativesMaturingInYearFour
Namespace Prefix:	pcar_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Notional maturities for all interest-rate contracts during fiscal year three.

+ References

No definition available.

+ Details

Name:	pcar_NotionalAmountOfInterestRateDerivativesMaturingInYearThree
Namespace Prefix:	pcar_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Notional maturities for all interest-rate contracts during fiscal year two.

+ References

No definition available.

+ Details

Name:	pcar_NotionalAmountOfInterestRateDerivativesMaturingInYearTwo
Namespace Prefix:	pcar_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-1

+ Details

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

- Definition

Amount as of the balance sheet date of the unamortized adjustment to the carrying value of an interest-bearing hedged item made under an effective fair value hedge that is amortized upon discontinuation of the fair value hedge.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 25
-Name Accounting Standards Codification
-Section 35
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480295/815-25-35-9

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

+ Details

Name:	us-gaap_DerivativeNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Period remaining until the derivative contract matures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeRemainingMaturity1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

No definition available.

+ Details

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

- Definition

Maximum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-SubTopic 30
-Topic 815
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-1

+ Details

Name:	us-gaap_MaximumLengthOfTimeHedgedInCashFlowHedge1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

PACCAR FINANCIAL CORP 10-Q