Fair Value Measurements and Derivatives (Tables)
   | 
9 Months Ended | 
Sep. 30, 2017  | 
| Schedule of derivatives measured at fair value and disclosed by balance sheet location | 
|   | 
  | 
  | 
  | 
Asset | 
  | 
  | 
Liability | 
  | 
 
|   | 
  | 
Balance Sheet location | 
  | 
September 30, 2017 | 
  | 
  | 
December 31, 2016 | 
  | 
  | 
September 30, 2017 | 
  | 
  | 
December 31, 2016 | 
  | 
 
| Fuel swaps designated as hedging instruments | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
|   | 
  | 
Prepaid expenses and other assets | 
  | 
$ | 
5,796 | 
  | 
  | 
$ | 
20,288 | 
  | 
  | 
$ | 
— | 
  | 
  | 
$ | 
— | 
  | 
 
|   | 
  | 
Other long-term assets | 
  | 
  | 
4,636 | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
1,903 | 
  | 
  | 
  | 
— | 
  | 
 
|   | 
  | 
Accrued expenses and other liabilities | 
  | 
  | 
4,237 | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
26,069 | 
  | 
  | 
  | 
44,271 | 
  | 
 
|   | 
  | 
Other long-term liabilities | 
  | 
  | 
7,724 | 
  | 
  | 
  | 
13,237 | 
  | 
  | 
  | 
17,578 | 
  | 
  | 
  | 
38,608 | 
  | 
 
| Foreign currency forward contracts designated as hedging instruments | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
|   | 
  | 
Prepaid expenses and other assets | 
  | 
  | 
41,983 | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
1,354 | 
  | 
  | 
  | 
— | 
  | 
 
|   | 
  | 
Other long-term assets | 
  | 
  | 
65,780 | 
  | 
  | 
  | 
14 | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
 
|   | 
  | 
Accrued expenses and other liabilities | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
61,788 | 
  | 
 
|   | 
  | 
Other long-term liabilities | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
88,920 | 
  | 
 
| Interest rate swaps designated as hedging instruments | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
|   | 
  | 
Accrued expenses and other liabilities | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
1,876 | 
  | 
  | 
  | 
3,331 | 
  | 
 
|   | 
  | 
Other long-term liabilities | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
1,151 | 
  | 
 
 
 | 
| Schedule of amounts recognized within assets and liabilities | 
| September 30, 2017 | 
  | 
Gross Amounts | 
  | 
  | 
Gross Amounts Offset | 
  | 
  | 
Total Net Amounts | 
  | 
  | 
Gross Amounts Not Offset | 
  | 
  | 
Net Amounts | 
  | 
 
| Assets | 
  | 
$ | 
118,195 | 
  | 
  | 
$ | 
(3,257 | 
) | 
  | 
$ | 
114,938 | 
  | 
  | 
$ | 
(100,582 | 
) | 
  | 
$ | 
14,356 | 
  | 
 
| Liabilities | 
  | 
  | 
45,523 | 
  | 
  | 
  | 
(11,961 | 
) | 
  | 
  | 
33,562 | 
  | 
  | 
  | 
(1,876 | 
) | 
  | 
  | 
31,686 | 
  | 
 
 
   
| December 31, 2016 | 
  | 
Gross Amounts | 
  | 
  | 
Gross Amounts Offset | 
  | 
  | 
Total Net Amounts | 
  | 
  | 
Gross Amounts Not Offset | 
  | 
  | 
Net Amounts | 
  | 
 
| Assets | 
  | 
$ | 
20,302 | 
  | 
  | 
$ | 
— | 
  | 
  | 
$ | 
20,302 | 
  | 
  | 
$ | 
(14 | 
) | 
  | 
$ | 
20,288 | 
  | 
 
| Liabilities | 
  | 
  | 
238,069 | 
  | 
  | 
  | 
(13,237 | 
) | 
  | 
  | 
224,832 | 
  | 
  | 
  | 
(155,190 | 
) | 
  | 
  | 
69,642 | 
  | 
 
 
 | 
| Fuel Swaps | Designated as Hedging Instrument | 
 
 | 
| Schedule of effects of derivatives designated and dedesignated as cash flow hedges | 
|   | 
  | 
Three Months Ended September 30, | 
  | 
  | 
Nine Months Ended September 30, | 
  | 
 
|   | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
 
| Gain (loss) recognized in other comprehensive income  – effective portion | 
  | 
$ | 
30,452 | 
  | 
  | 
$ | 
(157 | 
) | 
  | 
$ | 
(635 | 
) | 
  | 
$ | 
76,145 | 
  | 
 
| Gain (loss) recognized in other income (expense), net – ineffective portion | 
  | 
  | 
496 | 
  | 
  | 
  | 
(2,602 | 
) | 
  | 
  | 
(305 | 
) | 
  | 
  | 
(11,353 | 
) | 
 
| Amount reclassified from accumulated other comprehensive income (loss) into fuel expense | 
  | 
  | 
9,795 | 
  | 
  | 
  | 
16,427 | 
  | 
  | 
  | 
26,382 | 
  | 
  | 
  | 
68,004 | 
  | 
 
 
 | 
| Fuel Swaps | Not Designated as Hedging Instrument | 
 
 | 
| Schedule of effects of derivatives not designated as cash flow hedges | 
|   | 
  | 
Three Months Ended September 30, | 
  | 
  | 
Nine Months Ended September 30, | 
  | 
 
|   | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
 
| Loss recognized in other income (expense), net | 
  | 
$ | 
— | 
  | 
  | 
$ | 
(179 | 
) | 
  | 
$ | 
— | 
  | 
  | 
$ | 
(271 | 
) | 
 
| Amount reclassified from accumulated other comprehensive income (loss) into other income (expense), net | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
2,994 | 
  | 
 
 
 | 
| Foreign Currency Options | Designated as Hedging Instrument | 
 
 | 
| Schedule of effects of derivatives designated and dedesignated as cash flow hedges | 
|   | 
  | 
Three Months Ended September 30, | 
  | 
  | 
Nine Months Ended September 30, | 
  | 
 
|   | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
 
| Amount reclassified from accumulated other comprehensive income (loss) into depreciation and amortization expense | 
  | 
$ | 
330 | 
  | 
  | 
$ | 
330 | 
  | 
  | 
$ | 
990 | 
  | 
  | 
$ | 
990 | 
  | 
 
 
 | 
| Foreign Currency Forward Contracts | Designated as Hedging Instrument | 
 
 | 
| Schedule of effects of derivatives designated and dedesignated as cash flow hedges | 
|   | 
  | 
Three Months Ended September 30, | 
  | 
  | 
Nine Months Ended September 30, | 
  | 
 
|   | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
 
| Gain recognized in other comprehensive income – effective portion | 
  | 
$ | 
66,849 | 
  | 
  | 
$ | 
36,390 | 
  | 
  | 
$ | 
221,913 | 
  | 
  | 
$ | 
39,001 | 
  | 
 
| Loss recognized in other income (expense), net – ineffective portion | 
  | 
  | 
— | 
  | 
  | 
  | 
(190 | 
) | 
  | 
  | 
(66 | 
) | 
  | 
  | 
(181 | 
) | 
 
| Amount reclassified from accumulated other comprehensive income (loss) into depreciation and amortization expense | 
  | 
  | 
918 | 
  | 
  | 
  | 
665 | 
  | 
  | 
  | 
2,192 | 
  | 
  | 
  | 
1,966 | 
  | 
 
 
 | 
| Foreign Currency Forward Contracts | Not Designated as Hedging Instrument | 
 
 | 
| Schedule of effects of derivatives not designated as cash flow hedges | 
|   | 
  | 
Three Months Ended September 30, | 
  | 
  | 
Nine Months Ended September 30, | 
  | 
 
|   | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
 
| Loss recognized in other income (expense), net | 
  | 
$ | 
— | 
  | 
  | 
$ | 
— | 
  | 
  | 
$ | 
— | 
  | 
  | 
$ | 
(6,133 | 
) | 
 
 
 | 
| Foreign Currency Collar | Designated as Hedging Instrument | 
 
 | 
| Schedule of effects of derivatives designated and dedesignated as cash flow hedges | 
|   | 
  | 
Three Months Ended September 30, | 
  | 
  | 
Nine Months Ended September 30, | 
  | 
 
|   | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
 
| Amount reclassified from accumulated other comprehensive income (loss) into depreciation and amortization expense | 
  | 
$ | 
(91 | 
) | 
  | 
$ | 
(91 | 
) | 
  | 
$ | 
(273 | 
) | 
  | 
$ | 
(273 | 
) | 
 
 
 | 
| Foreign Currency Collar | Not Designated as Hedging Instrument | 
 
 | 
| Schedule of effects of derivatives not designated as cash flow hedges | 
|   | 
  | 
Three Months Ended September 30, | 
  | 
  | 
Nine Months Ended September 30, | 
  | 
 
|   | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
 
| Gain recognized in other income (expense), net | 
  | 
$ | 
— | 
  | 
  | 
$ | 
— | 
  | 
  | 
$ | 
— | 
  | 
  | 
$ | 
10,312 | 
  | 
 
 
 | 
| Interest Rate Swap | Designated as Hedging Instrument | 
 
 | 
| Schedule of effects of derivatives designated and dedesignated as cash flow hedges | 
|   | 
  | 
Three Months Ended September 30, | 
  | 
  | 
Nine Months Ended September 30, | 
  | 
 
|   | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
  | 
2017 | 
  | 
  | 
2016 | 
  | 
 
| Gain (loss) recognized in other comprehensive income – effective portion | 
  | 
$ | 
(25 | 
) | 
  | 
$ | 
818 | 
  | 
  | 
$ | 
234 | 
  | 
  | 
$ | 
(2,638 | 
) | 
 
| Gain recognized in other income (expense), net – ineffective portion | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
— | 
  | 
  | 
  | 
3 | 
  | 
 
| Amount reclassified from accumulated other comprehensive income (loss) into interest expense, net | 
  | 
  | 
691 | 
  | 
  | 
  | 
996 | 
  | 
  | 
  | 
2,301 | 
  | 
  | 
  | 
2,977 | 
  | 
 
 
 |