v3.7.0.1
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2017
Jul. 12, 2017
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
Trading Symbol UAL  
Entity Registrant Name United Continental Holdings, Inc.  
Entity Central Index Key 0000100517  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   304,225,391
United Airlines, Inc.    
Document Information [Line Items]    
Entity Registrant Name United Airlines, Inc.  
Entity Central Index Key 0000319687  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   1,000