Document And Entity Information	6 Months Ended
	Jun. 30, 2013	Aug. 01, 2013 Common Class A [Member]	Aug. 01, 2013 Common Class B [Member]
Document Information [Line Items]
Entity Registrant Name	RUSH ENTERPRISES INC \TX\
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		28,803,237	10,708,683
Amendment Flag	false
Entity Central Index Key	0001012019
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Jun. 30, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2