AIRCRAFT - Aircraft Maintenance Deposits Contra-Assets and Over-market Liabilities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) aircraft	Dec. 31, 2021 USD ($)
AIRCRAFT - Owned and Leased
Number of aircraft modified to finance leases | aircraft	2
Amount reclassified to finance lease, right-of-use asset	$ 9,687
Over-market maintenance reserve liability reclassified to finance lease liability	6,023
Aircraft maintenance deposits contra assets
AIRCRAFT - Owned and Leased
Remaining unamortized balance contra assets	22,348	$ 22,348
Over-market lease rates
AIRCRAFT - Owned and Leased
Remaining unamortized balance contra assets	383	10,363
Over market liabilities	7,793	$ 14,737
Reduction in over-market maintenance reserve liabilities	$ 6,944