Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements and Derivatives - Derivatives measured at fair value and disclosed by balance sheet location (Details)

v3.19.3.a.u2
Fair Value Measurements and Derivatives - Derivatives measured at fair value and disclosed by balance sheet location (Details) - USD ($)
$ in Thousands
Dec. 31, 2019
Dec. 31, 2018
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value $ 277 $ 12,125
Derivative liabilities, fair value 192,034 116,352
Designated as Hedging Instrument    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 3,429 17,217
Derivative liabilities, fair value 192,034 117,879
Fuel contracts | Designated as Hedging Instrument | Prepaid expenses and other assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value   2,583
Derivative liabilities, fair value   1
Fuel contracts | Designated as Hedging Instrument | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 277 197
Derivative liabilities, fair value   29
Fuel contracts | Designated as Hedging Instrument | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 2,300 1,173
Derivative liabilities, fair value 18,257 19,547
Fuel contracts | Designated as Hedging Instrument | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 683 933
Derivative liabilities, fair value 17,763 51,184
Foreign currency contracts | Designated as Hedging Instrument | Prepaid expenses and other assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value   5,285
Derivative liabilities, fair value   1,497
Foreign currency contracts | Designated as Hedging Instrument | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value   3,514
Foreign currency contracts | Designated as Hedging Instrument | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value   112
Derivative liabilities, fair value 33,475 5,145
Foreign currency contracts | Designated as Hedging Instrument | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 169 2,874
Derivative liabilities, fair value 118,500 40,476
Interest rate contracts | Designated as Hedging Instrument | Prepaid expenses and other assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value   519
Interest rate contracts | Designated as Hedging Instrument | Other long-term assets    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value   $ 27
Interest rate contracts | Designated as Hedging Instrument | Accrued expenses and other liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value 2,178  
Interest rate contracts | Designated as Hedging Instrument | Other long-term liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value $ 1,861