Borrowings and Credit Arrangements - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Apr. 30, 2016 MXN	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2016 MXN	Dec. 31, 2016 USD ($)	Dec. 31, 2016 EUR (€)
Debt Disclosure [Line Items]
Interest paid on borrowings		$ 108,200,000	$ 101,300,000	$ 136,300,000
Line of credit, maximum capacity						$ 3,431,000,000
Line of credit, unused borrowing capacity						3,223,400,000
Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity						3,000,000,000
PACCAR's U.S. finance subsidiary | Medium-term Notes
Debt Disclosure [Line Items]
Debt outstanding						4,750,000,000
Registration expiration		2018-11
PACCAR's European finance subsidiary | Medium-term Notes
Debt Disclosure [Line Items]
Debt, unused borrowing capacity | €							€ 1,313,400,000
Debt, borrowing capacity | €							€ 2,500,000,000
Debt, renewal period		Annually through the filing of new listing particulars
PACCAR's Mexico finance subsidiary | Commercial Papers
Debt Disclosure [Line Items]
Maximum limit of borrowing capacity | MXN	MXN 5,000,000,000
PACCAR's Mexico finance subsidiary | Medium-term Notes
Debt Disclosure [Line Items]
Registration expiration		2021-04
Debt, unused borrowing capacity | MXN					MXN 8,880,000,000
PACCAR's Mexico finance subsidiary | Medium-term Notes | Commercial Papers
Debt Disclosure [Line Items]
Debt, borrowing capacity | MXN	MXN 10,000,000,000
Financial Services
Debt Disclosure [Line Items]
Commercial paper and term notes borrowings			8,415,400,000			8,270,200,000
Fair value hedges and unamortized discounts, net		$ (19,300,000)	(11,200,000)
Truck, Parts and Other
Debt Disclosure [Line Items]
Capitalized interest				$ 1,300,000
Maximum | PACCAR's Mexico finance subsidiary | Commercial Papers
Debt Disclosure [Line Items]
Commercial paper expiration period	1 year
Expires in June 2017 | Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity						1,000,000,000
Line of credit, expiry date		2017-06
Expires in June 2020 | Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity						1,000,000,000
Line of credit, expiry date		2020-06
Expires in June 2021 | Syndicated loan facility
Debt Disclosure [Line Items]
Line of credit, maximum capacity						$ 1,000,000,000
Line of credit, expiry date		2021-06