OPERATING SEGMENT INFORMATION (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Operating revenues
Total Operating Revenues		$ 8,781	$ 8,264		$ 7,894
Operating expenses
Operating expenses, excluding fuel		5,840	5,685		5,239
Special items - merger-related costs		44	87		116
Economic fuel		1,878	1,936		1,447
Total Operating Expenses		7,718	7,621		6,686
Non-operating Income (Expense)
Interest income		42	38		34
Interest expense		(78)	(91)		(103)
Interest capitalized		15	18		17
Other - net		(26)	(23)		3
Nonoperating Income (Expense) Total		(47)	(58)		(49)
Income (loss) before income tax		1,016	585		1,159
Depreciation		423	398		372
Total property and equipment additions		(696)	(960)		(1,026)
Total assets		12,993	10,912
Air Group Adjusted [Member]
Operating revenues
Total Operating Revenues	[1]	8,781	8,264		7,894
Operating expenses
Operating expenses, excluding fuel	[1]	5,796	5,553		5,123
Economic fuel	[1]	1,884	1,914		1,454
Total Operating Expenses	[1]	7,680	7,467		6,577
Non-operating Income (Expense)
Interest income		42	38		34
Interest expense		(78)	(91)		(103)
Interest capitalized		15	18		17
Other - net		(26)	(23)		3
Nonoperating Income (Expense) Total	[1]	(47)	(58)		(49)
Income (loss) before income tax	[1]	1,054	739		1,268
Horizon [Member]
Operating revenues
Total Operating Revenues		451	512		430
Operating expenses
Operating expenses, excluding fuel		385	465		427
Economic fuel		0	0		0
Total Operating Expenses		385	465		427
Non-operating Income (Expense)
Interest income		0	0		0
Interest expense		(28)	(22)		(13)
Interest capitalized		0	2		2
Other - net		0	0		0
Nonoperating Income (Expense) Total		(28)	(20)		(11)
Income (loss) before income tax		38	27		(8)
Depreciation		86	82		64
Total property and equipment additions		(91)	(389)		(292)
Total assets		1,266	1,229
Parent [Member]
Non-operating Income (Expense)
Total assets		(7,480)	(7,170)
Intersegment Eliminations
Operating revenues
Total Operating Revenues		(445)	(508)		(426)
Operating expenses
Operating expenses, excluding fuel		(464)	(513)		(427)
Economic fuel		0	0		0
Total Operating Expenses		(464)	(513)		(427)
Non-operating Income (Expense)
Interest income		(24)	(15)		(5)
Interest expense		26	13		2
Interest capitalized		0	0		0
Other - net		0	0		0
Nonoperating Income (Expense) Total		2	(2)		(3)
Income (loss) before income tax		21	3		(2)
Special Charges [Member]
Operating revenues
Total Operating Revenues	[2]	0	0		0
Operating expenses
Operating expenses, excluding fuel		44	132	[2]	116	[2]
Economic fuel		(6)	22	[2]	(7)	[2]
Total Operating Expenses	[2]	38	154		109
Non-operating Income (Expense)
Interest income		0	0		0
Interest expense		0	0		0
Interest capitalized		0	0		0
Other - net		0	0		0
Nonoperating Income (Expense) Total	[2]	0	0		0
Income (loss) before income tax	[2]	(38)	(154)		(109)
Alaska Mainline [Member]
Operating revenues
Total Operating Revenues		7,381	7,063		6,832
Operating expenses
Operating expenses, excluding fuel		4,778	4,577		4,271
Economic fuel		1,589	1,652		1,282
Total Operating Expenses		6,367	6,229		5,553
Non-operating Income (Expense)
Interest income		66	53		39
Interest expense		(76)	(82)		(92)
Interest capitalized		15	16		15
Other - net		(26)	(12)		3
Nonoperating Income (Expense) Total		(21)	(25)		(35)
Income (loss) before income tax		993	809		1,244
Depreciation	[3]	337	316		308
Total property and equipment additions	[3]	(605)	(571)		(734)
Total assets	[3]	19,207	16,853
Alaska Regional [Member]
Operating revenues
Total Operating Revenues		1,394	1,197		1,058
Operating expenses
Operating expenses, excluding fuel		1,097	1,024		852
Economic fuel		295	262		172
Total Operating Expenses		1,392	1,286		1,024
Non-operating Income (Expense)
Interest income		0	0		0
Interest expense		0	0		0
Interest capitalized		0	0		0
Other - net		0	(11)		0
Nonoperating Income (Expense) Total		0	(11)		0
Income (loss) before income tax		2	(100)		34
Passenger Revenue [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		8,095	7,631		7,301
Passenger Revenue [Member] | Air Group Adjusted [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	8,095	7,631		7,301
Passenger Revenue [Member] | Horizon [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		0	0		0
Passenger Revenue [Member] | Intersegment Eliminations
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		0	0		0
Passenger Revenue [Member] | Special Charges [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax	[2]	0	0		0
Passenger Revenue [Member] | Alaska Mainline [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		6,750	6,474		6,278
Passenger Revenue [Member] | Alaska Regional [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		1,345	1,157		1,023
Capacity Purchase Agreements [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		0	0		0
Capacity Purchase Agreements [Member] | Air Group Adjusted [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	0	0		0
Capacity Purchase Agreements [Member] | Horizon [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		450	508		426
Capacity Purchase Agreements [Member] | Intersegment Eliminations
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		(450)	(508)		(426)
Capacity Purchase Agreements [Member] | Special Charges [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax	[2]	0	0		0
Capacity Purchase Agreements [Member] | Alaska Mainline [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		0	0		0
Capacity Purchase Agreements [Member] | Alaska Regional [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		0	0		0
Mileage Plan Services, Other [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		465	434		418
Mileage Plan Services, Other [Member] | Air Group Adjusted [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	465	434		418
Mileage Plan Services, Other [Member] | Horizon [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		0	0		0
Mileage Plan Services, Other [Member] | Intersegment Eliminations
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		0	0		0
Mileage Plan Services, Other [Member] | Special Charges [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax	[2]	0	0		0
Mileage Plan Services, Other [Member] | Alaska Mainline [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		419	397		387
Mileage Plan Services, Other [Member] | Alaska Regional [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		46	37		31
Cargo and Freight [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		221	199		175
Cargo and Freight [Member] | Air Group Adjusted [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	221	199		175
Cargo and Freight [Member] | Horizon [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		1	4		4
Cargo and Freight [Member] | Intersegment Eliminations
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		5	0		0
Cargo and Freight [Member] | Special Charges [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax	[2]	0	0		0
Cargo and Freight [Member] | Alaska Mainline [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		212	192		167
Cargo and Freight [Member] | Alaska Regional [Member]
Operating revenues
Revenue from Contract with Customer, Excluding Assessed Tax		$ 3	$ 3		$ 4

[1] Year Ended December 31, 2017MainlineRegionalHorizon Consolidating & Other^(a) Air Group Adjusted^(b) Special Items^(c) ConsolidatedOperating Revenues   Passenger revenues6,278  1,023  —  —  7,301  —  7,301  CPA revenues—  —  426  (426) —  —  —  Mileage Plan other revenue387  31  —  —  418  —  418  Cargo and other167  4  4  —  175  —  175  Total Operating Revenues6,832  1,058  430  (426) 7,894  —  7,894  Operating ExpensesNon-fuel operating expenses4,271  852  427  (427) 5,123  116  5,239  Fuel expense1,282  172  —  —  1,454  (7) 1,447  Total Operating Expenses5,553  1,024  427  (427) 6,577  109  6,686  Non-operating Income (Expense)Interest income39  —  —  (5) 34  —  34  Interest expense(92) —  (13) 2  (103) —  (103) Interest capitalized15  —  2  —  17  —  17  Other3  —  —  —  3  —  3  Total Non-operating Income (Expense)(35) —  (11) (3) (49) —  (49) Income (Loss) Before Income Tax$1,244  $34  $(8) $(2) $1,268  $(109) $1,159  

[2] Year Ended December 31, 2017MainlineRegionalHorizon Consolidating & Other^(a) Air Group Adjusted^(b) Special Items^(c) ConsolidatedOperating Revenues   Passenger revenues6,278  1,023  —  —  7,301  —  7,301  CPA revenues—  —  426  (426) —  —  —  Mileage Plan other revenue387  31  —  —  418  —  418  Cargo and other167  4  4  —  175  —  175  Total Operating Revenues6,832  1,058  430  (426) 7,894  —  7,894  Operating ExpensesNon-fuel operating expenses4,271  852  427  (427) 5,123  116  5,239  Fuel expense1,282  172  —  —  1,454  (7) 1,447  Total Operating Expenses5,553  1,024  427  (427) 6,577  109  6,686  Non-operating Income (Expense)Interest income39  —  —  (5) 34  —  34  Interest expense(92) —  (13) 2  (103) —  (103) Interest capitalized15  —  2  —  17  —  17  Other3  —  —  —  3  —  3  Total Non-operating Income (Expense)(35) —  (11) (3) (49) —  (49) Income (Loss) Before Income Tax$1,244  $34  $(8) $(2) $1,268  $(109) $1,159  

[3] INCOME TAXES Deferred Income Taxes
Deferred income taxes reflect the impact of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and such amounts for tax purposes. The Company has a net deferred tax liability, primarily due to differences in depreciation rates for federal income tax purposes and for financial reporting purposes. Deferred tax (assets) and liabilities comprise the following (in millions):  20192018Excess of tax over book depreciation$1,233  $1,066  Intangibles - net16  15  Operating lease liabilities416  —  Other - net58  43  Deferred tax liabilities1,723  1,124  Mileage Plan™(337) (315) Inventory obsolescence(15) (15) Employee benefits(179) (172) Acquired net operating losses(13) (64) Operating lease assets(417) —  Other - net(48) (48) Deferred tax assets(1,009) (614) Valuation allowance1  2  Net deferred tax liabilities$715  $512  
At December 31, 2019, the Company had federal NOLs of approximately $45 million that expire beginning in 2032 and continuing through 2036, and state NOLs of approximately $55 million that expire beginning in 2029 and continuing through 2036.
Virgin America experienced multiple “ownership changes” as defined in Section 382 of the Internal Revenue Code of 1986, as amended (the “Code”), the most recent being its acquisition by the Company. Section 382 of the Code imposes an annual limitation on the utilization of pre-ownership change NOLs. Any unused annual limitation may, subject to certain limits, be carried over to later years. The combined Company’s ability to use the NOLs will also depend on the amount of taxable income generated in future periods.
Valuation allowances are provided to reduce the related deferred income tax assets to an amount which will, more likely than not, be realized. The valuation allowance was not material at both December 31, 2019 and December 31, 2018.
Components of Income Tax Expense
The components of income tax expense are as follows (in millions):   201920182017Current income tax expense (benefit):   Federal$26  $(5) $127  State13  9  35  Total current income tax expense39  4  162  Deferred income tax expense (benefit):         Federal175  125  (3) State33  19  40  Total deferred income tax expense (benefit)208  144  37  Income tax expense$247  $148  $199   Income Tax Rate Reconciliation
Income tax expense reconciles to the amount computed by applying the 2019 U.S. federal rate of 21% to income before income tax and for deferred taxes as follows (in millions):    201920182017Income before income tax$1,016  $585  $1,159  Expected tax expense213  123  406  Nondeductible expenses9  9  5  State income taxes36  21  28  State income sourcing1  —  9  Tax law changes(9) (7) (237) Other - net(3) 2  (12) Actual tax expense$247  $148  $199  Effective tax rate24.3 %25.3 %17.2 %   As a result of the ASC 606 full retrospective adoption, 2017 tax expense increased by $26 million.
As a result of tax changes signed into law during 2017, with final regulations issued in 2019, the Company recorded a deferred tax benefit of $9 million in the current year.
In 2017, adjustments were made to the Company's position on income sourcing in various states due to updated guidance from state taxing authorities. The impact of this guidance is reflected as an increase in income tax expense of approximately $9 million for the year ended December 31, 2017.
Uncertain Tax Positions
The Company has identified its federal tax return and its state tax returns in Alaska, Oregon and California as “major” tax jurisdictions.  A summary of the Company's jurisdictions and the periods that are subject to examination are as follows: JurisdictionPeriodFederal2007 to 2018Alaska2015 to 2018California2007 to 2018Oregon2003 to 2018
Certain tax years are open to the extent of net operating loss carryforwards.
Changes in the liability for gross unrecognized tax benefits during 2019, 2018 and 2017 are as follows (in millions): 201920182017Balance at January 1,$40  $43  $40  Additions related to prior years—  1  16  Releases related to prior years(1) (4) (2) Additions related to current year activity2  2  2  Releases due to settlements—  (1) (11) Releases due to lapse of statute of limitations(1) (1) (2) Balance at December 31,$40  $40  $43  
As of December 31, 2019, the Company had $40 million of accrued tax contingencies, of which $34 million, if fully recognized, would decrease the effective tax rate. As of December 31, 2019, 2018 and 2017, the Company has accrued interest and penalties, net of federal income tax benefit, of $7 million, $6 million, and $5 million. In 2019, 2018, and 2017, the Company recognized an expense of $1 million, $1 million, and $2 million for interest and penalties, net of federal income tax benefit. At December 31, 2019, the Company has unrecognized tax benefits recorded as a liability and some reducing deferred tax assets. The Company's reserves for uncertain tax positions is unchanged in 2019 after statute lapses on reserves and current year activity. These uncertain tax positions could change as a result of the Company's ongoing audits, settlement of issues, new audits and status of other taxpayer court cases. The Company cannot predict the timing of these actions. Due to the positions being taken in various jurisdictions, the amounts currently accrued are the Company's best estimate as of December 31, 2019.