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)

v3.20.1
Fair Value Measurements and Derivatives - Derivatives Measured at Fair Value and Disclosed by Balance Sheet Location (Details) - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value $ 1,411 $ 277
Derivative liabilities, fair value 451,791 192,034
Designated as Hedging Instrument    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 1,411 3,429
Derivative liabilities, fair value 438,172 192,034
Derivative Contracts Not Designated as Hedging Instruments    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 0
Derivative liabilities, fair value 13,619 0
Fuel contracts | Designated as Hedging Instrument | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 277
Derivative liabilities, fair value 0 0
Fuel contracts | Designated as Hedging Instrument | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 2,300
Derivative liabilities, fair value 93,109 18,257
Fuel contracts | Designated as Hedging Instrument | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 683
Derivative liabilities, fair value 110,085 17,763
Fuel contracts | Derivative Contracts Not Designated as Hedging Instruments | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 0
Derivative liabilities, fair value 13,619 0
Foreign currency contracts | Designated as Hedging Instrument | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 1,411 0
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 0
Derivative liabilities, fair value 15,581 33,475
Foreign currency contracts | Designated as Hedging Instrument | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 169
Derivative liabilities, fair value 206,917 118,500
Interest Rate Swap [Member] | Designated as Hedging Instrument | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 0
Derivative liabilities, fair value 7,790 2,178
Interest Rate Swap [Member] | Designated as Hedging Instrument | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 0 0
Derivative liabilities, fair value 4,690 1,861
Total derivatives    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 1,411 3,429
Derivative liabilities, fair value $ 451,791 $ 192,034