Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements and Derivatives - Effects of cash flow hedge accounting on consolidated statements of operations (Details)

v3.19.3.a.u2
Fair Value Measurements and Derivatives - Effects of cash flow hedge accounting on consolidated statements of operations (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Derivative Instruments Gain Loss [Line Items]      
Fuel $ 409,602 $ 392,685 $ 361,032
Depreciation and amortization 646,188 561,060 509,957
Interest expense, net 272,867 270,404 267,804
Cash Flow Hedging      
Derivative Instruments Gain Loss [Line Items]      
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     361,032
Depreciation and amortization     509,957
Interest expense, net     (267,804)
Cash Flow Hedging | 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)
Cash Flow Hedging | 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)
Cash Flow Hedging | 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)
Cash Flow Hedging | 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  
Cash Flow Hedging | 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)  
Cash Flow Hedging | 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)  
Designated as Hedging Instrument | Cash Flow Hedging | Fuel contracts      
Derivative Instruments Gain Loss [Line Items]      
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (before ASU adoption)     (29,721)
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency contracts      
Derivative Instruments Gain Loss [Line Items]      
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (before ASU adoption)     (4,077)
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate contracts      
Derivative Instruments Gain Loss [Line Items]      
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (before ASU adoption)     $ (2,997)