Firm Commitments to Purchase Aircraft (Detail) (United Airlines, Inc., Capital Addition Purchase Commitments)	Mar. 31, 2014 Aircraft
Airbus A350-1000 aircraft
Commitments [Line Items]
Number of new aircraft committed to purchase	35	[1]
Boeing 737-900ER aircraft
Commitments [Line Items]
Number of new aircraft committed to purchase	53	[1]
Boeing 737 MAX 9 Aircraft
Commitments [Line Items]
Number of new aircraft committed to purchase	100	[1]
Boeing 787-8/-9/-10
Commitments [Line Items]
Number of new aircraft committed to purchase	55	[1]
Embraer EMB175 aircraft
Commitments [Line Items]
Number of new aircraft committed to purchase	29	[1]

[1] United also has options and purchase rights for additional aircraft.