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)

v3.19.3
Fair Value Measurements and Derivatives - Derivatives measured at fair value and disclosed by balance sheet location (Details) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value $ 770 $ 12,125
Derivative liabilities, fair value 331,803 116,352
Designated as Hedging Instrument    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 381 17,217
Derivative liabilities, fair value 332,149 117,879
Derivative Contracts Not Designated as Hedging Instruments    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 1,162 0
Derivative liabilities, fair value 0 0
Fuel contracts | Designated as Hedging Instrument | Prepaid expenses and other assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 50 2,583
Derivative liabilities, fair value 346 1
Fuel contracts | Designated as Hedging Instrument | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 53 197
Derivative liabilities, fair value 0 29
Fuel contracts | Designated as Hedging Instrument | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 17 1,173
Derivative liabilities, fair value 35,439 19,547
Fuel contracts | Designated as Hedging Instrument | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 261 933
Derivative liabilities, fair value 36,233 51,184
Fuel contracts | Derivative Contracts Not Designated as Hedging Instruments | Prepaid expenses and other assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 667 0
Derivative liabilities, fair value 0 0
Fuel contracts | Derivative Contracts Not Designated as Hedging Instruments | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 495 0
Derivative liabilities, fair value 0 0
Foreign currency contracts | Designated as Hedging Instrument | Prepaid expenses and other assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 5,285
Derivative liabilities, fair value 0 1,497
Foreign currency contracts | Designated as Hedging Instrument | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 3,514
Derivative liabilities, fair value 0 0
Foreign currency contracts | Designated as Hedging Instrument | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 112
Derivative liabilities, fair value 97,524 5,145
Foreign currency contracts | Designated as Hedging Instrument | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 2,874
Derivative liabilities, fair value 156,339 40,476
Interest rate contracts | Designated as Hedging Instrument | Prepaid expenses and other assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 519
Derivative liabilities, fair value 0 0
Interest rate contracts | Designated as Hedging Instrument | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 27
Derivative liabilities, fair value 0 0
Interest rate contracts | Designated as Hedging Instrument | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 0
Derivative liabilities, fair value 2,984 0
Interest rate contracts | Designated as Hedging Instrument | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 0
Derivative liabilities, fair value 3,284 0
Total derivatives    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 1,543 17,217
Derivative liabilities, fair value $ 332,149 $ 117,879