COMMITMENTS AND CONTINGENCIES - Aircraft Commitments by Fleet Type (Details) - Aircraft purchase commitments - aircraft	Jun. 30, 2026	Mar. 31, 2026
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	332
A220-300
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	58
A321-200neo
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	90
A330-900neo
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	16
A350-900
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	18
A350-1000
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	20
B-737-10
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	100
B-787-10
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	30
Boeing 787-10
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required		30
Airbus A330-900 Aircraft
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required		16
Airbus A350-900 Aircraft
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required		15
Widebody Aircraft
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required		20
Airbus A321neo Aircraft
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required		34
Aircraft purchase commitments, maximum quantity required		36