Derivative Instruments (Notional And Fair Value Of Derivative Instruments) (Details)	3 Months Ended
	Jun. 30, 2014 USD ($)		Dec. 31, 2013 JPY (¥)	Jun. 30, 2014 Designated as Hedging Instrument [Member] USD ($)	Jun. 30, 2014 Interest Rate Swap - LT [Member] USD ($)		Jun. 30, 2014 Interest Rate Swap - LT [Member] JPY (¥)	Jun. 30, 2014 Other Liabilities [Member] Interest Rate Swap - LT [Member] USD ($)		Jun. 30, 2014 Other Current Assets [Member] Foreign Exchange Contracts [Member] USD ($)	Jun. 30, 2014 Other Assets [Member] Foreign Exchange Contracts [Member] USD ($)	Jun. 30, 2014 Oslo Bulk, AS [Member] USD ($)	Jun. 30, 2013 Oslo Bulk, AS [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives, current notional amount	$ 31,612,000									$ 3,392,000	$ 28,219,000
Liability derivatives, current notional amount					46,482,000	[1]
Derivatives, current notional amount	46,482,000	[2]	3,300,000,000	78,093,000
Asset derivatives, fair value				413,000						69,000	344,000
Liability derivatives, fair value				(3,895,000)				(3,895,000)	[1]
Exchange rate			102.53				101.33
Original funding of vessel's delivery cost (in hundredths)	80.00%
Revised funding of vessel's delivery cost (in hundredths)	65.00%
Reduction in funding of vessel's delivery cost (in hundredths)	15.00%
Change in fair value related to ineffective portion of derivative instrument, loss	18,000
Negative balance related to an interest rate swap in Oslo Bulk AS												$ 555,000
Ownership percentage (in hundredths)												25.00%	25.00%

[1] We have outstanding a variable-to-fixed interest rate swap with respect to a Yen-based facility for the financing of a PCTC delivered in March 2010. The notional amount under this contract is $46.5 million (based on a Yen to USD exchange rate of 101.33 as of June 30, 2014). With the bank exercising its option to reduce the underlying Yen loan from 80% to 65% funding of the vessel’s delivery cost, the 15% reduction represents the ineffective portion of this swap, which consists of the portion of the derivative instrument that is no longer supported by underlying borrowings. The change in fair value related to the ineffective portion of this swap is reflected in our statement of income (loss) for the second quarter of 2014 as a $18,000 loss. The fair value balance as of June 30, 2014, includes a negative $555,000 balance related to an interest rate swap associated with our 25% investment in Oslo Bulk AS.

[2] Notional amount converted from Yen at June 30, 2014 at a Yen to USD exchange rate of 101.33.