Annual Minimum Payments Due on Finance Receivables (Detail) (Financial Services, USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivables	$ 9,065.1us-gaap_NotesReceivableGross	$ 8,820.1us-gaap_NotesReceivableGross
Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
2015	1,251.2
2016	1,032.1
2017	815.3
2018	523.8
2019	296.2
Thereafter	49.9
Financing Receivables	3,968.5
Finance Leases Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
2015	1,066.9
2016	905.7
2017	691.6
2018	448.0
2019	265.7
Thereafter	143.7
Financing Receivables	$ 3,521.6

Amount of minimum payments due after the fifth fiscal year following the latest fiscal year on finance receivables.

No definition available.

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- Definition

Amount of minimum payments due in the fifth fiscal year following the latest fiscal year on finance receivables.

+ References

No definition available.

+ Details

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- Definition

Amount of minimum payments due in the fourth fiscal year following the latest fiscal year on finance receivables.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Amount of minimum payments due in the third fiscal year following the latest fiscal year on finance receivables.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Amount of minimum payments due in the second fiscal year following the latest fiscal year on finance receivables.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Amount of minimum payments due in the next fiscal year following the latest fiscal year on finance receivables.

+ References

No definition available.

+ Details

Name:	pcar_FinanceReceivablesMinimumPaymentsDueWithinOneYear
Namespace Prefix:	pcar_
Data Type:	xbrli:monetaryItemType
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- Details

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

- Definition

Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10(3))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Subparagraph 3

-Article 9

+ Details

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