v2.4.0.8
Document and Entity Information
6 Months Ended
Jun. 30, 2014
Jul. 18, 2014
Document and Entity Information [Abstract]    
Document type 10-Q  
Document period end date Jun. 30, 2014  
Amendment flag false  
Entity registrant name UNION PACIFIC CORPORATION  
Entity central index key 0000100885  
Entity current reporting status Yes  
Entity voluntary filers No  
Current fiscal year end date --12-31  
Entity filer category Large Accelerated Filer  
Entity well known seasoned issuer Yes  
Entity common stock shares outstanding   897,427,875
Document fiscal year focus 2014  
Document fiscal period focus Q2