Goodwill and Other Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 4,523		$ 4,523
Finite-lived intangible assets, Gross Carrying Amount	1,791		1,804
Finite-lived intangible assets, Accumulated Amortization	1,049		933
Indefinite-lived intangible assets, Gross Carrying Amount	3,542		3,565
Hubs
Goodwill And Intangible Assets [Line Items]
Asset life	20 years	[1]
Finite-lived intangible assets, Gross Carrying Amount	145		145
Finite-lived intangible assets, Accumulated Amortization	67		59
Patents And Trade Names
Goodwill And Intangible Assets [Line Items]
Asset life	3 years	[1]
Finite-lived intangible assets, Gross Carrying Amount	108		108
Finite-lived intangible assets, Accumulated Amortization	108		108
Frequent Flyer Database
Goodwill And Intangible Assets [Line Items]
Asset life	22 years	[1],[2]
Finite-lived intangible assets, Gross Carrying Amount	1,177	[2]	1,177	[2]
Finite-lived intangible assets, Accumulated Amortization	624	[2]	536	[2]
Contracts
Goodwill And Intangible Assets [Line Items]
Asset life	12 years	[1]
Finite-lived intangible assets, Gross Carrying Amount	155		167
Finite-lived intangible assets, Accumulated Amortization	86		86
Other Intangible Assets
Goodwill And Intangible Assets [Line Items]
Asset life	25 years	[1]
Finite-lived intangible assets, Gross Carrying Amount	109		109
Finite-lived intangible assets, Accumulated Amortization	67		56
Route Authorities
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, Gross Carrying Amount	1,589		1,605
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
Airport Slots And Gates
Goodwill And Intangible Assets [Line Items]
Asset life	8 years	[1]
Finite-lived intangible assets, Gross Carrying Amount	97		98
Finite-lived intangible assets, Accumulated Amortization	97		88
Indefinite-lived intangible assets, Gross Carrying Amount	$ 956		$ 963

[1] Weighted average life expressed in years.

[2] The frequent flyer database is 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 database is considered in the determination of the amortization schedules.