Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements and Derivatives - Effects of Derivatives Designated as Cash Flow Hedges (Details 2)

v3.8.0.1
Fair Value Measurements and Derivatives - Effects of Derivatives Designated as Cash Flow Hedges (Details 2) - Cash Flow Hedging - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of gain or (loss) recognized in other comprehensive income $ 48,576 $ (7,283)
Amount reclassified from accumulated other comprehensive income (loss) into fuel expense 1,785 (9,705)
Fuel Swaps | Fuel    
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of gain or (loss) recognized in other comprehensive income (6,012) (26,203)
Amount reclassified from accumulated other comprehensive income (loss) into fuel expense 3,525 (8,003)
Foreign currency forward contracts | Depreciation and amortization expense    
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of gain or (loss) recognized in other comprehensive income 54,493 18,636
Amount reclassified from accumulated other comprehensive income (loss) into fuel expense (1,159) (857)
Interest Rate Swap | Interest expense, net    
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of gain or (loss) recognized in other comprehensive income 95 284
Amount reclassified from accumulated other comprehensive income (loss) into fuel expense $ (581) $ (845)