Other Liabilities (Tables)
 12 Months Ended
Dec. 31, 2016
Other Liabilities Disclosure [Abstract]  
Schedule of Other Liabilities
 
As of December 31,
 
2016
 
2015
Port Authority terminal obligations
$
7,305

 
$
7,850

Postretirement benefit obligations
3,671

 
4,030

Other
1,814

 
3,115

Other liabilities
$
12,790

 
$
14,995