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The net effect of fair value hedges, unamortized discounts and unamortized debt issuance costs on commercial paper and term notes.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

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Amount of cash paid for interest, including, but not limited to, capitalized interest and payment to settle zero-coupon bond attributable to accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount; classified as operating and investing activities.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Borrowings and Credit Arrangements - Additional Information (Detail) € in Millions, R$ in Millions, $ in Millions, $ in Millions, $ in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Apr. 30, 2016 MXN ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jan. 31, 2024 USD ($)	Dec. 31, 2023 EUR (€)	Dec. 31, 2023 MXN ($)	Dec. 31, 2023 AUD ($)	Dec. 31, 2023 CAD ($)	Dec. 31, 2023 BRL (R$)
Debt Disclosure [Line Items]
Interest paid on borrowings		$ 396.5	$ 169.1	$ 104.8
Line of credit, maximum capacity		4,198.8
Line of credit, unused borrowing capacity		3,657.7
Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity		3,000.0
Line of credit, outstanding amount		0.0
Expires in June 2024 \| Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity		$ 1,000.0
Line of credit, expiry date		2024-06
Expires in June 2026 \| Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity		$ 1,000.0
Line of credit, expiry date		2026-06
Expires in June 2028 \| Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity		$ 1,000.0
Line of credit, expiry date		2028-06
PACCAR's U.S. finance subsidiary \| Medium-term Notes
Debt Disclosure [Line Items]
Debt outstanding		$ 6,100.0
Registration expiration		2024-11
PACCAR's U.S. finance subsidiary \| Medium-term Notes \| Subsequent Event
Debt Disclosure [Line Items]
Debt outstanding					$ 600.0
PACCAR's Brazilian finance subsidiary \| Medium-term Notes
Debt Disclosure [Line Items]
Debt outstanding \| R$										R$ 775.5
Debt, borrowing capacity \| R$										R$ 1,148.0
PACCAR's European finance subsidiary \| Medium-term Notes
Debt Disclosure [Line Items]
Debt, unused borrowing capacity \| €						€ 911.7
Debt, borrowing capacity \| €						€ 2,500.0
Debt, renewal period		This program renews annually and expires in September 2024.
PACCAR's Mexico finance subsidiary \| Commercial Paper
Debt Disclosure [Line Items]
Maximum limit of borrowing capacity	$ 5,000.0
PACCAR's Mexico finance subsidiary \| Commercial Paper \| Maximum
Debt Disclosure [Line Items]
Commercial paper expiration period	1 year
PACCAR's Mexico finance subsidiary \| Medium-term Notes
Debt Disclosure [Line Items]
Registration expiration			2026-08
Debt, unused borrowing capacity							$ 6,324.8
PACCAR's Mexico finance subsidiary \| Medium-term Notes \| Commercial Paper
Debt Disclosure [Line Items]
Debt, borrowing capacity	$ 10,000.0
PACCAR's Australian subsidiary \| Medium-term Notes
Debt Disclosure [Line Items]
Debt outstanding								$ 850.0
PACCAR Canadian subsidiary \| Medium-term Notes
Debt Disclosure [Line Items]
Debt outstanding									$ 150.0
Financial Services
Debt Disclosure [Line Items]
Commercial paper and term notes borrowings		$ 13,693.5	$ 11,132.2
Fair value hedges and unamortized discounts, net		$ (54.1)	$ (55.8)