Credit Arrangements - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Line of Credit Facility [Line Items]
Credit facility available amount	$ 3,000.0
Company and PACCAR and Other non-U.S. PACCAR Financial Subsidiaries
Line of Credit Facility [Line Items]
Credit facility available amount	2,268.0
PACCAR and Other non-U.S. PACCAR Financial Subsidiaries
Line of Credit Facility [Line Items]
Credit facility available amount	732.0
Committed bank facility
Line of Credit Facility [Line Items]
Line of credit, maximum capacity	3,000.0
Committed bank facility | Matures in June 2024
Line of Credit Facility [Line Items]
Line of credit, maximum capacity	$ 1,000.0
Line of credit, maturity date	2024-06
Committed bank facility | Matures in June 2026
Line of Credit Facility [Line Items]
Line of credit, maximum capacity	$ 1,000.0
Line of credit, maturity date	2026-06
Committed bank facility | Matures in June 2028
Line of Credit Facility [Line Items]
Line of credit, maximum capacity	$ 1,000.0
Line of credit, maturity date	2028-06