Accounts Payable And Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts Payable And Accrued Liabilities [Abstract]
Accrued Voyage Expenses	$ 36,365	$ 37,977
Trade Accounts Payable	9,343	5,301
Accrued Salaries and Benefits	2,472	3,845
Lease Incentive Obligation	1,901	1,901
Self-Insurance Liability	1,165	1,187
Accrued Insurance Premiums	1,187	891
Short Term Derivatives Liability	298	60
Straight Line Charter Escalation		58
Accounts Payable and Accrued Liabilities	$ 52,731	$ 51,220