Commitments and Contingencies (Commitments) (Details)	Sep. 30, 2016 USD ($)
Long-term Purchase Commitment [Line Items]
aircraft under modification	7
costs to complete aircraft modification	$ 291,800,000

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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