Borrowings and Credit Arrangements - Additional Information (Detail) $ in Millions, $ in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Apr. 30, 2016 MXN ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jan. 31, 2023 USD ($)	Dec. 31, 2022 EUR (€)	Dec. 31, 2022 MXN ($)	Dec. 31, 2022 AUD ($)	Dec. 31, 2022 CAD ($)
Debt Disclosure [Line Items]
Interest paid on borrowings		$ 169.1	$ 104.8	$ 164.5
Line of credit, maximum capacity		3,698.0
Line of credit, unused borrowing capacity		3,358.6
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 2019 | Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity		$ 1,000.0
Line of credit, expiry date		2023-06
Expires in June 2022 | Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity		$ 1,000.0
Line of credit, expiry date		2025-06
Expires in June 2023 | Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity		$ 1,000.0
Line of credit, expiry date		2027-06
PACCAR's U.S. finance subsidiary | Medium-term Notes
Debt Disclosure [Line Items]
Debt outstanding		$ 5,850.0
Registration expiration		2024-11
PACCAR's U.S. finance subsidiary | Medium-term Notes | Subsequent Event
Debt Disclosure [Line Items]
Debt outstanding					$ 300.0
PACCAR's European finance subsidiary | Medium-term Notes
Debt Disclosure [Line Items]
Debt, unused borrowing capacity | €						€ 1,117,800,000
Debt, borrowing capacity | €						€ 2,500,000,000.0
Debt, expiration		2023-07
Debt, renewal period		This program renews annually and expires in July 2023.
PACCAR's Mexico finance subsidiary | Commercial Paper
Debt Disclosure [Line Items]
Maximum limit of borrowing capacity	$ 5,000,000,000.0
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							$ 9,079,000,000.0
PACCAR's Mexico finance subsidiary | Medium-term Notes | Commercial Paper
Debt Disclosure [Line Items]
Debt, borrowing capacity	$ 10,000,000,000.0
PACCAR's Australian subsidiary | Medium-term Notes
Debt Disclosure [Line Items]
Debt outstanding								$ 700.0
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		$ 11,132.2	10,153.9
Fair value hedges and unamortized discounts, net		$ (55.8)	$ (21.6)