XML 37 R1.htm IDEA: XBRL DOCUMENT v2.4.0.8
Document And Entity Information
 9 Months Ended
Sep. 30, 2014
Nov. 01, 2014
Common Class A [Member]
Nov. 01, 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   29,850,692 10,054,930
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 Sep. 30, 2014    
Document Fiscal Year Focus 2014    
Document Fiscal Period Focus Q3