Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Nov. 01, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	0-20797
Entity Registrant Name	RUSH ENTERPRISES, INC.
Entity Incorporation, State or Country Code	TX
Entity Tax Identification Number	74-1733016
Entity Address, Address Line One	555 I.H. 35 South, Suite 500
Entity Address, City or Town	New Braunfels
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78130
City Area Code	830
Local Phone Number	302-5200
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001012019
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false
Common Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		62,331,889
Title of 12(b) Security	Class A Common Stock, $0.01 par value
Trading Symbol	RUSHA
Security Exchange Name	NASDAQ
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		16,694,547
Title of 12(b) Security	Class B Common Stock, $0.01 par value
Trading Symbol	RUSHB
Security Exchange Name	NASDAQ