Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2023	Jan. 31, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Trading Symbol	PCAR26
Entity Registrant Name	PACCAR FINANCIAL CORP
Entity Central Index Key	0000731288
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		145,000
Entity Public Float			$ 0
Entity File Number	001-11677
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	91-6029712
Entity Address, Address Line One	777 106th Avenue N.E.
Entity Address, City or Town	Bellevue
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98004
City Area Code	425
Local Phone Number	468-7100
Title of 12(b) Security	Series P Medium-Term Notes$300.0 Million Due May 11, 2026
Security Exchange Name	NASDAQ
Document Annual Report	true
Document Transition Report	false
Document Financial Statement Error Correction [Flag]	false
Auditor Firm ID	42
Auditor Name	Ernst & Young LLP
Auditor Location	Seattle, Washington
ICFR Auditor Attestation Flag	false
Documents Incorporated by Reference	THE REGISTRANT IS A WHOLLY OWNED SUBSIDIARY OF PACCAR INC AND MEETS THE CONDITIONS SET FORTH IN GENERAL INSTRUCTIONS (I) (1) (a) AND (b) OF FORM 10-K AND IS, THEREFORE, FILING THIS FORM WITH THE REDUCED DISCLOSURE FORMAT.