| 
           Fair Value Measurements and Derivatives (Tables)
  
         | 
        12 Months Ended | 
      
      
        | 
           Dec. 31, 2013 
         | 
      
      
        | Derivatives Measured at Fair Value and Disclosed by Balance Sheet Location | 
        
 
 The following
 table sets forth our derivatives measured at fair value and
 discloses the balance sheet location (in thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 |   | 
    | 
 
  
 Balance
 Sheet location 
  | 
    | 
 Asset | 
   | 
    | 
 Liability | 
   | 
  
 
 |    | 
    | 
 December 31, 
 2013 | 
   | 
    | 
 December 31, 
 2012 | 
   | 
    | 
 December 31, 
 2013 | 
   | 
    | 
 December 31, 
 2012 | 
   | 
  
 
 | 
  Fuel swaps designated as
 hedging instruments 
  | 
    | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Prepaid expenses and other
 assets 
  | 
    | 
 $ | 
 5,024 | 
    | 
    | 
 $ | 
 5,955 | 
    | 
    | 
 $ | 
 666 | 
    | 
    | 
 $ | 
 876 | 
    | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Other long-term
 assets 
  | 
    | 
   | 
 6,869 | 
    | 
    | 
   | 
 3,969 | 
    | 
    | 
   | 
 9 | 
   | 
    | 
   | 
 388 | 
    | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Accrued expenses and other
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 188 | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 204 | 
    | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Other long-term
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 391 | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 42 | 
    | 
  
 
 | 
  Fuel collars designated as
 hedging instruments 
  | 
    | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Prepaid expenses and other
 assets 
  | 
    | 
   | 
 452 | 
    | 
    | 
   | 
 1,615 | 
    | 
    | 
   | 
 195 | 
    | 
    | 
   | 
 530 | 
    | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Accrued expenses and other
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 51 | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 69 | 
    | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Other long-term
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 1,908 | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 1,230 | 
    | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 | 
  Fuel options not designated
 as hedging instruments 
  | 
    | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Prepaid expenses and other
 assets 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 195 | 
    | 
    | 
   | 
 304 | 
    | 
  
 
  | 
    | 
 
  Other long-term
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 1,231 | 
    | 
  
 
 | 
  Foreign currency options
 designated as hedging instruments 
  | 
    | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Accrued expenses and other
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 9,815 | 
    | 
    | 
   | 
 20,267 | 
    | 
  
 
  | 
    | 
 
  Other long-term
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 16,443 | 
    | 
  
 
 | 
  Foreign currency forward
 contracts designated as hedging instruments 
  | 
    | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Prepaid expenses and other
 assets 
  | 
    | 
   | 
 2,624 | 
    | 
    | 
   | 
 11,685 | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Accrued expenses and other
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 6,582 | 
    | 
    | 
   | 
 —   | 
    | 
  
 
 | 
  Foreign currency collar
 designated as a hedging instrument 
  | 
    | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Prepaid expenses and other
 assets 
  | 
    | 
   | 
 12,502 | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
  
 
  | 
    | 
 
  Other long-term
 assets 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 9,765 | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 1,613 | 
    | 
  
 
 | 
  Interest rate swaps
 designated as hedging instruments 
  | 
    | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
    | 
  | 
  | 
  | 
  
 
  | 
    | 
 
  Accrued expenses and other
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 1,707 | 
    | 
    | 
   | 
 —   | 
    | 
  
 
  | 
    | 
 
  Other long-term
 liabilities 
  | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
    | 
   | 
 1,374 | 
   | 
    | 
   | 
 —   | 
    | 
  
  
  
 | 
      
      
        | Amounts Recognized Within Assets and Liabilities | 
        
 
 The following
 table discloses the amounts recognized within assets and
 liabilities (in thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 | 
  
 December 31, 2013 
  | 
    | 
 Gross Amounts | 
   | 
    | 
 Gross 
 Amounts 
 Offset | 
   | 
   | 
 Total Net 
 Amounts | 
   | 
    | 
 Gross 
 Amounts Not 
 Offset | 
   | 
   | 
 Net Amounts | 
   | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 | 
  Assets 
  | 
    | 
 $ | 
 27,471 | 
    | 
    | 
 $ | 
 (1,065 | 
 )  | 
   | 
 $ | 
 26,406 | 
    | 
    | 
 $ | 
 (15,126 | 
 ) | 
   | 
 $ | 
 11,280 | 
    | 
  
 
 | 
  Liabilities 
  | 
    | 
   | 
 19,478 | 
    | 
    | 
   | 
 —   | 
    | 
   | 
   | 
 19,478 | 
    | 
    | 
   | 
 (19,478 | 
 )  | 
   | 
   | 
 —   | 
    | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 | 
  
 December 31,
 2012 
  | 
    | 
 Gross Amounts | 
   | 
    | 
 Gross 
 Amounts 
 Offset | 
   | 
   | 
 Total Net 
 Amounts | 
   | 
    | 
 Gross 
 Amounts Not 
 Offset | 
   | 
   | 
 Net Amounts | 
   | 
  
 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 | 
  Assets 
  | 
    | 
 $ | 
 32,989 | 
    | 
    | 
 $ | 
 (3,711 | 
 )  | 
   | 
 $ | 
 29,278 | 
    | 
    | 
 $ | 
 (11,685 | 
 )  | 
   | 
 $ | 
 17,593 | 
    | 
  
 
 | 
  Liabilities 
  | 
    | 
   | 
 39,486 | 
    | 
    | 
   | 
 (2,538 | 
 )  | 
   | 
   | 
 36,948 | 
    | 
    | 
   | 
 (36,710 | 
 )  | 
   | 
   | 
 238 | 
    | 
  
  
  
 | 
      
      
        | 
           Fuel Swaps 
         | 
         
 | 
      
      
        | Effects of Derivatives Designated as Cash Flow Hedges | 
        
 
 The effects on
 the consolidated financial statements of the fuel swaps which were
 designated as cash flow hedges were as follows (in
 thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 |   | 
    | 
 Year Ended
 December 31, | 
   | 
  
 
 |   | 
    | 
 2013 | 
   | 
   | 
 2012 | 
   | 
   | 
 2011 | 
   | 
  
 
 | 
  Gain recognized in other
 comprehensive income (loss) – effective portion 
  | 
    | 
 $ | 
 8,532 | 
    | 
   | 
 $ | 
 18,906 | 
    | 
   | 
 $ | 
 29,928 | 
    | 
  
 
 | 
  Gain (loss) recognized in
 other income (expense) – ineffective portion 
  | 
    | 
   | 
 (345 | 
 )  | 
   | 
   | 
 (509 | 
 )  | 
   | 
   | 
 457 | 
    | 
  
 
 | 
  Amount reclassified from
 accumulated other comprehensive income (loss) into fuel
 expense 
  | 
    | 
   | 
 (6,250 | 
 )  | 
   | 
   | 
 (14,448 | 
 )  | 
   | 
   | 
 (36,686 | 
 )  | 
  
  
  
 | 
      
      
        | 
           Fuel Options 
         | 
         
 | 
      
      
        | Effects of Derivatives Not Designated as Cash flow Hedges | 
        
 
 The effects of
 the fuel options on the consolidated financial statements which
 were not designated as hedging instruments were as follows (in
 thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 |   | 
    | 
 Year Ended
 December 31, | 
   | 
  
 
 |   | 
    | 
 2013 | 
   | 
    | 
 2012 | 
   | 
    | 
 2011 | 
   | 
  
 
 | 
  Gain recognized in other
 income (expense) 
  | 
    | 
 $ | 
 1,340 | 
    | 
    | 
 $ | 
 3,218 | 
    | 
    | 
 $ | 
 2,422 | 
    | 
  
  
  
 | 
      
      
        | 
           Foreign Exchange Forward 
         | 
         
 | 
      
      
        | Effects of Derivatives Designated as Cash Flow Hedges | 
        
 
 The effects on
 the consolidated financial statements of the foreign currency
 forward contracts which were designated as cash flow hedges were as
 follows (in thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 |   | 
    | 
 Year Ended
 December 31, | 
   | 
  
 
 |   | 
    | 
 2013 | 
   | 
   | 
 2012 | 
   | 
    | 
 2011 | 
   | 
  
 
 | 
  Gain (loss) recognized in
 other comprehensive income (loss) – effective
 portion 
  | 
    | 
 $ | 
 (2,983 | 
 )  | 
   | 
 $ | 
 11,685 | 
    | 
    | 
 $ | 
 —   | 
    | 
  
 
 | 
  Loss recognized in other
 income (expense) – ineffective portion 
  | 
    | 
   | 
 67 | 
   | 
   | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
  
 
 | 
  Amount reclassified from
 accumulated comprehensive income (loss) into depreciation and
 amortization expense 
  | 
    | 
   | 
 (84 | 
 )  | 
   | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
  
  
  
 | 
      
      
        | Effects of Derivatives Not Designated as Cash flow Hedges | 
        
 
 As of
 December 31, 2013, the effects on the consolidated financial
 statements of the foreign currency forward contracts which were not
 designated as hedging instruments were as follows (in
 thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 |   | 
    | 
 Year Ended December 31, | 
   | 
  
 
 |   | 
    | 
 2013 | 
   | 
    | 
 2012 | 
   | 
    | 
 2011 | 
   | 
  
 
 | 
  Gain recognized in other
 income (expense) 
  | 
    | 
 $ | 
 20 | 
    | 
    | 
 $ | 
 —   | 
    | 
    | 
 $ | 
 —   | 
    | 
  
  
  
 | 
      
      
        | 
           Fuel Collars 
         | 
         
 | 
      
      
        | Effects of Derivatives Designated as Cash Flow Hedges | 
        
 
 The effects on
 the consolidated financial statements of the fuel collars which
 were designated as cash flow hedges were as follows (in
 thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 |   | 
    | 
 Year Ended
 December 31, | 
   | 
  
 
 |   | 
    | 
 2013 | 
   | 
   | 
 2012 | 
   | 
   | 
 2011 | 
   | 
  
 
 | 
  Gain (loss) recognized in
 other comprehensive income (loss) – effective
 portion 
  | 
    | 
 $ | 
 (1,152 | 
 )  | 
   | 
 $ | 
 592 | 
    | 
   | 
 $ | 
 (147 | 
 )  | 
  
 
 | 
  Gain (loss) recognized in
 other income (expense) – ineffective portion 
  | 
    | 
   | 
 (26 | 
 )  | 
   | 
   | 
 165 | 
    | 
   | 
   | 
 (302 | 
 )  | 
  
 
 | 
  Amount reclassified from
 accumulated other comprehensive income (loss) into fuel
 expense 
  | 
    | 
   | 
 1,547 | 
    | 
   | 
   | 
 (1,954 | 
 )  | 
   | 
   | 
 —   | 
    | 
  
  
  
 | 
      
      
        | 
           Foreign Exchange Option 
         | 
         
 | 
      
      
        | Effects of Derivatives Designated as Cash Flow Hedges | 
        
 
 The effects on
 the consolidated financial statements of the foreign currency
 options which were designated as cash flow hedges were as follows
 (in thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 |   | 
    | 
 Year Ended
 December 31, | 
   | 
  
 
 |   | 
    | 
 2013 | 
   | 
   | 
 2012 | 
   | 
   | 
 2011 | 
   | 
  
 
 | 
  Loss recognized in other
 comprehensive loss – effective portion 
  | 
    | 
 $ | 
 (3,304 | 
 )  | 
   | 
 $ | 
 (19,428 | 
 )  | 
   | 
 $ | 
 (14,583 | 
 )  | 
  
 
 | 
  Loss recognized in other
 income (expense) – ineffective portion 
  | 
    | 
   | 
 (97 | 
 )  | 
   | 
   | 
 (864 | 
 )  | 
   | 
   | 
 (239 | 
 )  | 
  
 
 | 
  Amount reclassified from
 accumulated comprehensive income (loss) into depreciation and
 amortization expense 
  | 
    | 
   | 
 470 | 
    | 
   | 
   | 
 —   | 
    | 
   | 
   | 
 —   | 
    | 
  
  
  
 | 
      
      
        | 
           Foreign Currency Collar 
         | 
         
 | 
      
      
        | Effects of Derivatives Designated as Cash Flow Hedges | 
        
 
 The effects on
 the consolidated financial statements of the foreign currency
 collar which was designated as a cash flow hedge was as follows (in
 thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 |   | 
    | 
 Year Ended
 December 31, | 
   | 
  
 
 |   | 
    | 
 2013 | 
   | 
    | 
 2012 | 
   | 
    | 
 2011 | 
   | 
  
 
 | 
  Gain recognized in other
 comprehensive income (loss) – effective portion 
  | 
    | 
 $ | 
 4,350 | 
    | 
    | 
 $ | 
 8,152 | 
    | 
    | 
 $ | 
 —   | 
    | 
  
  
  
 | 
      
      
        | 
           Interest Rate Swap 
         | 
         
 | 
      
      
        | Effects of Derivatives Designated as Cash Flow Hedges | 
        
 
 The effects on
 the consolidated financial statements of the interest rates swaps
 which were designated as cash flow hedges were as follows (in
 thousands): 
 
   
 
 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  
 
 |   | 
    | 
 Year Ended
 December 31, | 
   | 
  
 
 |   | 
    | 
 2013 | 
   | 
   | 
 2012 | 
   | 
    | 
 2011 | 
   | 
  
 
 | 
  Loss recognized in other
 comprehensive income (loss) – effective portion 
  | 
    | 
 $ | 
 (3,196 | 
 )  | 
   | 
 $ | 
 —   | 
    | 
    | 
 $ | 
 —   | 
    | 
  
 
 | 
  Amount reclassified from
 other comprehensive income (loss) into interest expense,
 net 
  | 
    | 
   | 
 189 | 
    | 
   | 
   | 
 —   | 
    | 
    | 
   | 
 —   | 
    | 
  
  
  
 |