v2.4.0.6
Document And Entity Information
9 Months Ended
Sep. 30, 2012
Nov. 02, 2012
Common Class A [Member]
Nov. 02, 2012
Common Class B [Member]
Entity Registrant Name RUSH ENTERPRISES INC \TX\    
Document Type 10-Q    
Current Fiscal Year End Date --12-31    
Entity Common Stock, Shares Outstanding   27,933,473 10,792,223
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 Sep. 30, 2012    
Document Fiscal Year Focus 2012    
Document Fiscal Period Focus Q3