Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements and Derivatives - Effects of derivatives designated as cash flow hedges (Details)

v3.19.3.a.u2
Fair Value Measurements and Derivatives - Effects of derivatives designated as cash flow hedges (Details) - Cash Flow Hedging - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Recognized in Other Comprehensive Income $ (123,015) $ (161,214)  
Amount of Gain (Loss) Recognized in Other Comprehensive Income (before ASU adoption)     $ 304,684
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income 8,898 30,096  
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (before ASU adoption)     (36,795)
Fuel      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income 14,093 34,410  
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (before ASU adoption)     (29,721)
Depreciation and amortization      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (3,062) (3,463)  
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (before ASU adoption)     (4,077)
Interest expense, net      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (2,133) (851)  
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (before ASU adoption)     (2,997)
Fuel contracts      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Recognized in Other Comprehensive Income 46,154 (52,949)  
Amount of Gain (Loss) Recognized in Other Comprehensive Income (before ASU adoption)     50,263
Fuel contracts | Fuel      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income 14,093 34,410  
Foreign currency contracts      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Recognized in Other Comprehensive Income (163,197) (108,911)  
Amount of Gain (Loss) Recognized in Other Comprehensive Income (before ASU adoption)     254,070
Foreign currency contracts | Depreciation and amortization      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (3,062) (3,463)  
Interest rate contracts      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Recognized in Other Comprehensive Income (5,972) 646  
Amount of Gain (Loss) Recognized in Other Comprehensive Income (before ASU adoption)     $ 351
Interest rate contracts | Interest expense, net      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income $ (2,133) $ (851)