Restricted Cash (Details) (USD $)
In Thousands, unless otherwise specified
0 Months Ended 12 Months Ended 0 Months Ended
Nov. 05, 2014
item
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
May 14, 2013
Jun. 25, 2013
Nov. 13, 2013
item
Nov. 21, 2013
Oct. 14, 2014
Restricted cash                  
Restricted cash   $ 2,824 $ 14,717            
Current restricted cash   2,824 14,717            
Net proceeds from sale of vessels and deposits received   50,602 52,926 5,635          
Number of vessels acquired 2                
Interest rate swap contracts                  
Restricted cash                  
Current restricted cash     400            
Amalia C                  
Restricted cash                  
TEU   2,452     2,452        
Property, plant and equipment acquired   6,600     6,600        
MSC Zebra                  
Restricted cash                  
TEU   2,602       2,602      
Property, plant and equipment acquired   10,100       10,100      
Niledutch Palanca                  
Restricted cash                  
TEU   2,524              
Property, plant and equipment acquired   11,900              
Danae C                  
Restricted cash                  
TEU             2,524    
Property, plant and equipment acquired             11,900    
Dimitris C                  
Restricted cash                  
TEU   3,430           3,430  
Property, plant and equipment acquired   14,900           14,900  
MOL Performance                  
Restricted cash                  
TEU   6,402             6,402
Property, plant and equipment acquired                 18,250
MOL Priority                  
Restricted cash                  
TEU   6,402             6,402
Property, plant and equipment acquired                 18,250
Aegean Baltic Bank HSH Nordbank Piraeus Bank                  
Restricted cash                  
Current restricted cash     11,400            
Net proceeds from sale of vessels and deposits received   55,200              
Maximum | Aegean Baltic Bank HSH Nordbank Piraeus Bank                  
Restricted cash                  
Number of vessels that the company can sell under the option provided by the agreement   9              
Retention accounts                  
Restricted cash                  
Restricted cash   2,824 2,841            
Restricted deposits                  
Restricted cash                  
Restricted cash     $ 11,876