Commitments and Contingencies (Details) - USD ($)	Jun. 30, 2015	Dec. 31, 2014
Insurance Claims [Member]
Commitments and Contingencies (Textual) [Abstract]
Liability and cargo insurance coverage for claims	$ 500,000
Cargo Claims [Member]
Commitments and Contingencies (Textual) [Abstract]
Liability and cargo insurance coverage for claims	100,000
Uninsured Risk [Member]
Commitments and Contingencies (Textual) [Abstract]
Reserves for estimated uninsured losses	$ 5,900,000	$ 5,800,000