COMMITMENTS (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($) aircraft
B-737 [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Committed to Purchase (in Aircraft) | aircraft	32
Options to Purchase Additional (in Aircraft) | aircraft	37
A320neo [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Unrecorded Unconditional Purchase Obligation, Option to Cancel | aircraft	30
E175 [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Committed to Purchase (in Aircraft) | aircraft	3
Options to Purchase Additional (in Aircraft) | aircraft	30
SkyWest CPA E175 [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Property Subject to or Available for Operating Lease, Number of Optional Additional Units | aircraft	8
Aircraft Maintenance Deposits [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2018	$ 7
2019	35
2020	45
2021	24
2022	6
Thereafter	2
Total	119
Aircraft Commitments [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2018	343
2019	549
2020	333
2021	192
2022	21
Thereafter	25
Total	1,463
Capacity Purchase Agreements [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Remainder of 2018	36
2019	166
2020	174
2021	179
2022	184
Thereafter	880
Total	1,619
Virgin America Flight Attendants [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Loss Contingency, Damages Sought, Value	$ 78