ACQUISITION OF VIRGIN AMERICA, INC. Fair values of the assets acquired and the liabilities assumed (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 14, 2016
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill	$ 1,943	$ 1,934
Virgin America Inc. [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents			$ 645
Receivables			53
Prepaid expenses and other current assets			18
Property and equipment			571
Intangible assets			141
Goodwill			1,943
Other assets			89
Total assets			3,460
Accounts payable			22
Accrued wages, vacation and payroll taxes			54
Air traffic liabilities			172
Other accrued liabilities			198
Current portion of long-term debt			125
Long-term debt, net of current portion			360
Deferred income taxes			(300)
Deferred revenue			126
Other liabilities			107
Total liabilities			864
Total purchase price			2,596
Scenario, Previously Reported [Member] | Virgin America Inc. [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents			645
Receivables			44
Prepaid expenses and other current assets			16
Property and equipment			560
Intangible assets			143
Goodwill			1,934
Other assets			84
Total assets			3,426
Accounts payable			22
Accrued wages, vacation and payroll taxes			51
Air traffic liabilities			172
Other accrued liabilities			196
Current portion of long-term debt			125
Long-term debt, net of current portion			360
Deferred income taxes			(304)
Deferred revenue			126
Other liabilities			82
Total liabilities			830
Total purchase price			$ 2,596