Fair Value Measurements (Fair Value Measurements At Reporting Date Using) (Details) - Fuel Hedge Contracts [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Net Asset (Liability)	$ 869	$ 4,388
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Net Asset (Liability)	$ 869	$ 4,388

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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