Document And Entity Information	3 Months Ended
	Mar. 31, 2014	May 02, 2014 Common Class A [Member]	May 02, 2014 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		29,458,141	10,235,222
Amendment Flag	false
Entity Central Index Key	0001012019
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Mar. 31, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q1