ACQUISITION OF VIRGIN AMERICA, INC. (Details) $ in Millions				12 Months Ended
		Dec. 15, 2016 USD ($)	Dec. 14, 2016 USD ($) departures	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Business Acquisition [Line Items]
Number of Daily Departures | departures			1,200
Revenue				$ 5,931	$ 5,598	$ 5,368
Net Income				814	848	605
Goodwill				1,934	0
Repayments of related party debt		$ 55
Special items—merger-related costs and other				117	32	(30)
Virgin America Inc. [Member]
Business Acquisition [Line Items]
Percentage of interests acquired			100.00%
Revenue				99
Net Income				15
Goodwill			$ 1,934
Intangible assets			143
Finite-lived intangible assets acquired			54
Special items—merger-related costs and other				117
Airport Gates [Member] | Virgin America Inc. [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired			$ 14
Finite-Lived intangible asset, useful Life			12 years
Customer Relationships [Member] | Virgin America Inc. [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired			$ 40
Finite-Lived intangible asset, useful Life			8 years
Airport Slots [Member] | Virgin America Inc. [Member]
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired			$ 89
Special Charges [Member]
Business Acquisition [Line Items]
Revenue	[1]			$ 0	$ 0	$ 0

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