LONG-TERM DEBT - LINE OF CREDIT (Details) $ in Millions	Dec. 31, 2023 USD ($) credit_facility
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 626
Number of credit facilities | credit_facility	3
Line of credit facility, asset restrictions, unrestricted cash and marketable securities	$ 500
Credit Facility 1 [Member] | Secured by other [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	150
Credit Facility 2 [Member] | Secured by aircraft [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	400
Credit Facility 3 [Member] | Secured by aircraft [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 76