REVENUE - Significant Categories of Operating Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
REVENUE
Total Operating Revenues	$ 326,649	$ 311,483
Passenger
REVENUE
Total Operating Revenues	285,888	274,664
Scheduled Service
REVENUE
Total Operating Revenues	143,522	141,194
Charter
REVENUE
Total Operating Revenues	54,692	47,312
Ancillary
REVENUE
Total Operating Revenues	87,674	86,158
Cargo
REVENUE
Total Operating Revenues	28,157	23,948
Other
REVENUE
Total Operating Revenues	$ 12,604	$ 12,871