Operating Revenue by Principle Geographic Region (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Total revenues	$ 9,329	$ 10,228	$ 10,001	$ 8,721	$ 8,702	$ 9,909	$ 9,939	$ 8,602	$ 38,279	$ 37,152	$ 37,110
Domestic (U.S. and Canada)
Segment Reporting Information [Line Items]
Total revenues									22,092	21,276	21,922
Pacific
Segment Reporting Information [Line Items]
Total revenues									5,794	6,040	5,404
Atlantic
Segment Reporting Information [Line Items]
Total revenues									7,132	6,582	6,675
Latin America
Segment Reporting Information [Line Items]
Total revenues									3,261	3,254	3,109
United Airlines, Inc.
Segment Reporting Information [Line Items]
Total revenues									38,287	37,160	37,119
United Airlines, Inc. | Domestic (U.S. and Canada)
Segment Reporting Information [Line Items]
Total revenues									22,100	21,284	21,931
United Airlines, Inc. | Pacific
Segment Reporting Information [Line Items]
Total revenues									5,794	6,040	5,404
United Airlines, Inc. | Atlantic
Segment Reporting Information [Line Items]
Total revenues									7,132	6,582	6,675
United Airlines, Inc. | Latin America
Segment Reporting Information [Line Items]
Total revenues									$ 3,261	$ 3,254	$ 3,109