Goodwill and Other Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 4,523		$ 4,523
Finite-lived intangible assets, Gross Carrying Amount	1,805		1,806
Finite-lived intangible assets, Accumulated Amortization	792		670
Indefinite-lived intangible assets, Gross Carrying Amount	3,584		3,614
Airport Slots And Gates
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	99		100
Finite-lived intangible assets, Accumulated Amortization	75		61
Hubs
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	145		145
Finite-lived intangible assets, Accumulated Amortization	52		44
Patents And Trade Names
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	108		108
Finite-lived intangible assets, Accumulated Amortization	99		86
Frequent Flyer Database
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	1,177		1,177
Finite-lived intangible assets, Accumulated Amortization	447		381
Contracts
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	167		167
Finite-lived intangible assets, Accumulated Amortization	75		64
Other Intangible Assets
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	109		109
Finite-lived intangible assets, Accumulated Amortization	44		34
Airport Slots And Gates
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	981		1,011
Route Authorities
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	1,606		1,606
Tradenames And Logos
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	593		593
Alliances
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	404		404
United Air Lines Inc
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	960		961
Finite-lived intangible assets, Accumulated Amortization	588		534
Indefinite-lived intangible assets, Gross Carrying Amount	1,856		1,856
United Air Lines Inc | Airport Slots And Gates
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	72		72
Finite-lived intangible assets, Accumulated Amortization	59		52
Asset life	9 years	[1]
United Air Lines Inc | Hubs
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	145		145
Finite-lived intangible assets, Accumulated Amortization	52		44
Asset life	20 years	[1]
United Air Lines Inc | Frequent Flyer Database
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	521		521
Finite-lived intangible assets, Accumulated Amortization	327		296
Asset life	21 years	[1],[2]
United Air Lines Inc | Contracts
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	140		140
Finite-lived intangible assets, Accumulated Amortization	68		60
Asset life	13 years	[1]
United Air Lines Inc | Other Intangible Assets
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	12		13
Finite-lived intangible assets, Accumulated Amortization	12		12
Asset life	7 years	[1]
United Air Lines Inc | Patents
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	70		70
Finite-lived intangible assets, Accumulated Amortization	70		70
Asset life	3 years	[1]
United Air Lines Inc | Route Authorities
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	1,117		1,117
United Air Lines Inc | Alliances
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	118		118
United Air Lines Inc | Indefinite Lived Airport Slots
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	201		201
United Air Lines Inc | Indefinite Lived Trade Names
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	420		420
Continental Airlines Inc
Goodwill And Intangible Assets [Line Items]
Goodwill	4,523		4,523
Finite-lived intangible assets, Gross Carrying Amount	845		845
Finite-lived intangible assets, Accumulated Amortization	204		136
Indefinite-lived intangible assets, Gross Carrying Amount	1,730		1,760
Continental Airlines Inc | Airport Slots
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	27		28
Finite-lived intangible assets, Accumulated Amortization	16		9
Asset life	4 years	[1]
Continental Airlines Inc | Trade Names
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	38		38
Finite-lived intangible assets, Accumulated Amortization	29		16
Asset life	3 years	[1]
Continental Airlines Inc | Frequent Flyer Database
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	656		656
Finite-lived intangible assets, Accumulated Amortization	120		85
Asset life	23 years	[1],[2]
Continental Airlines Inc | Contracts
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	27		27
Finite-lived intangible assets, Accumulated Amortization	7		4
Asset life	10 years	[1]
Continental Airlines Inc | Other Intangible Assets
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	97		96
Finite-lived intangible assets, Accumulated Amortization	32		22
Asset life	27 years	[1]
Continental Airlines Inc | Route Authorities
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	489		489
Continental Airlines Inc | Tradenames And Logos
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	173		173
Continental Airlines Inc | Alliances
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	286		286
Continental Airlines Inc | Indefinite Lived Airport Slots
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	$ 782		$ 812

[1] Weighted average life expressed in years. UAL is covered by the weighted average of each of its individual subsidiaries.

[2] The United and Continental frequent flyer databases are amortized based on an accelerated amortization schedule to reflect utilization of the assets. Estimated cash flows correlating to the expected attrition rate of customers in the frequent flyer databases were considered in the determination of the amortization schedules.