Fair Value Assets Measured on Nonrecurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
United Continental Holdings Inc
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount	$ 11,477	$ 11,682
Fair Value	12,542	11,992
United Continental Holdings Inc | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	7,250	859
United Continental Holdings Inc | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	5,292	11,133
United Airlines Inc
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount	5,531	5,745
Fair Value	5,718	5,630
United Airlines Inc | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	2,197
United Airlines Inc | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	3,521	5,630
Continental Airlines Inc
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount	5,540	5,528
Fair Value	5,832	5,503
Continental Airlines Inc | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	4,061
Continental Airlines Inc | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	$ 1,771	$ 5,503