SPECIAL ITEMS SPECIAL ITEMS (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Merger-related Costs [Line Items]
Special items - merger-related costs	$ 44	$ 87	$ 116
Special items—other	0	45	0
Nondeductible expenses	9	9	5
Special tax expense (benefit)	0	0	(237)
Virgin America Inc. [Member]
Merger-related Costs [Line Items]
Special items - merger-related costs	44	$ 87	$ 116
Settlement Fee [Member]
Merger-related Costs [Line Items]
Special items—other	20
One-time Bonus Payment [Member]
Merger-related Costs [Line Items]
Special items—other	$ 25

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible expenses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration