LONG-TERM DEBT - LINE OF CREDIT (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Mar. 31, 2023
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 486
Line of Credit Facility, Asset Restrictions		500
Credit Facility 1 [Member] | Secured by certain accounts receivable, spare engines, spare parts and ground service equipment [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		150
Credit Facility 2 [Member] | Secured by aircraft [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		250
Credit Facility 3 [Member] | Secured by aircraft [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 86
US Treasury CARES Act Loan [Member]
Line of Credit Facility [Line Items]
Adjustments to Additional Paid in Capital, Warrant Issued	$ 30