Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements and Derivatives - Derivatives Measured at Fair Value and Disclosed by Balance Sheet Location (Details)

v3.5.0.2
Fair Value Measurements and Derivatives - Derivatives Measured at Fair Value and Disclosed by Balance Sheet Location (Details) - USD ($)
$ in Thousands
Sep. 30, 2016
Dec. 31, 2015
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value $ 42,335 $ 3,446
Derivative liabilities, fair value 159,777 344,619
Designated as Hedging Instrument | Fuel Swaps | Prepaid expenses and other assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 13,740
Derivative liabilities, fair value
Designated as Hedging Instrument | Fuel Swaps | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 3,462
Derivative liabilities, fair value 145
Designated as Hedging Instrument | Fuel Swaps | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value
Derivative liabilities, fair value 73,923 128,740
Designated as Hedging Instrument | Fuel Swaps | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 7,167
Derivative liabilities, fair value 65,529 132,494
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Prepaid expenses and other assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 10,153
Derivative liabilities, fair value 1,381
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 14,980 3,446
Derivative liabilities, fair value 2,363 1,370
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 1,065
Derivative liabilities, fair value 8,930 8,737
Designated as Hedging Instrument | Foreign Currency Forward Contracts | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 1,567 551
Derivative liabilities, fair value 4,943 24,181
Designated as Hedging Instrument | Interest Rate Swap | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value
Derivative liabilities, fair value 3,858 4,079
Designated as Hedging Instrument | Interest Rate Swap | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value
Derivative liabilities, fair value 2,594 3,395
Not Designated as Hedging Instrument | Foreign Currency Collar | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value
Derivative liabilities, fair value $ 42,993