LEASES, Operating Lease Terms (Details) - Aircraft  | 
Mar. 31, 2020  | 
Mar. 31, 2019  | 
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| Leases [Abstract] | ||
| Number of aircraft | 46 | 75 | 
| Fiscal year 2021 to fiscal year 2022 | ||
| Leases [Abstract] | ||
| Number of aircraft | 17 | |
| Fiscal year 2023 to fiscal year 2026 | ||
| Leases [Abstract] | ||
| Number of aircraft | 29 | 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition The number of units (items of property) under operating lease arrangements. No definition available. 
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- Details 
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- Details 
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