Deferred Charges (Rollforward of Deferred Charges) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($)
Deferred Charges [Abstract]
Drydocking Costs, Beginning Balance	$ 22,123
Drydocking Costs, Cash Additions	2,942
Drydocking Costs, Amortization	(3,079)
Drydocking Costs, Non-Cash Reclassifications	(80)
Drydocking Costs, Ending Balance	21,906
Other Deferred Charges, Beginning Balance	914
Other Deferred Charges, Amortization	(143)
Other Deferred Charges, Non-Cash Reclassifications	371
Other Deferred Charges, Ending Balance	1,142
Total Deferred Charges, Beginning Balance	23,037
Total Deferred Charges, Cash Additions	2,942
Total Deferred Charges, Amortization	(3,222)
Total Deferred Charges, Non-Cash Reclassifications	291
Total Deferred Charges, Ending Balance	$ 23,048