ORGANIZATION & BUSINESS - Schedule of Aircraft (Details)	Mar. 31, 2026 aircraft
Product Information [Line Items]
Number of aircraft	275
Total aircraft	283
Spare aircraft	8
E170
Product Information [Line Items]
Number of aircraft	25
E175
Product Information [Line Items]
Number of aircraft	250
American Airlines
Product Information [Line Items]
Number of aircraft	92
Number of aircraft leased	31
American Airlines | E170
Product Information [Line Items]
Number of aircraft	13
American Airlines | E175
Product Information [Line Items]
Number of aircraft	79
Delta Air Lines
Product Information [Line Items]
Number of aircraft	57
Delta Air Lines | E170
Product Information [Line Items]
Number of aircraft	11
Delta Air Lines | E175
Product Information [Line Items]
Number of aircraft	46
United Airlines
Product Information [Line Items]
Number of aircraft	126
United Airlines | E170
Product Information [Line Items]
Number of aircraft	1
United Airlines | E175
Product Information [Line Items]
Number of aircraft	125