Debt Obligations (Schedule Of Long-Term Debt) (Details) ¥ in Billions									1 Months Ended							3 Months Ended		12 Months Ended
		Nov. 13, 2015	Nov. 12, 2015 USD ($)	Nov. 04, 2015	Nov. 03, 2015	Apr. 24, 2015 JPY (¥)	Apr. 24, 2015 USD ($)	Aug. 26, 2014 USD ($) item	Jan. 31, 2016 USD ($)	Aug. 31, 2014 USD ($) item	Jan. 31, 2012 USD ($)	Dec. 31, 2011 USD ($) item	Nov. 30, 2011 USD ($)	Jun. 30, 2011 USD ($)	Aug. 31, 2010 USD ($) item	Dec. 31, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Nov. 15, 2015 USD ($)	Apr. 30, 2015 USD ($)
Debt Instrument [Line Items]
Total principal due																$ 159,844,000		$ 159,844,000	$ 242,888,000
Less current maturities																(156,807,000)		(156,807,000)	(23,367,000)
Less: Debt Issuance Costs																(3,037,000)		(3,037,000)	(2,870,000)
Long-Term Debt, Net																			216,651,000
Proceeds from borrowings of line of credit																		5,000,000	40,500,000
Pre-funding of upcoming quarterly debt payment, amount																$ 1,530,000		$ 1,530,000	1,394,000
Note Payable - Mortgage [Member]
Debt Instrument [Line Items]
Total principal due	[1]																		$ 5,000
Capital One N.A. [Member] | Notes Payable - Variable Rate 2017 [Member]
Debt Instrument [Line Items]
Interest rate	[2]															2.5938%		2.5938%	2.505%
Maturity date	[2]																	2017
Total principal due	[2]															$ 6,904,000		$ 6,904,000	$ 9,144,000
ING Bank [Member]
Debt Instrument [Line Items]
Term of financing agreement in years																		7 years
ING Bank [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate				4.50%	2.50%
ING Bank [Member] | Notes Payable - Variable Rate 2018, Tranche A [Member]
Debt Instrument [Line Items]
Interest rate	[3]															4.693%		4.693%	2.7471%
Maturity date	[3]																	2018
Total principal due	[3]															$ 8,589,000		$ 8,589,000	$ 12,025,000
Proceeds from borrowings of line of credit														$ 24,100,000	$ 36,800,000
ING Bank [Member] | Notes Payable - Variable Rate 2018, Tranche B [Member]
Debt Instrument [Line Items]
Debt instrument interst rate, minimum																		4.6947%	2.7312%
Debt instrument interest rate, maximum																		4.7336%	2.7324%
Maturity date	[3]																	2018
Total principal due	[3]															$ 25,146,000		$ 25,146,000	$ 41,400,000
Line of credit facility borrowing capacity														$ 23,300,000
Proceeds from borrowings of line of credit											$ 12,700,000		$ 6,100,000		$ 18,400,000
ING Bank [Member] | Notes Payable - Variable Rate 2018c [Member]
Debt Instrument [Line Items]
Interest rate	[3]															4.8199%		4.8199%	2.735%
Maturity date	[3]																	2018
Total principal due	[3]															$ 2,800,000		$ 2,800,000	$ 15,394,000
Handysize Vessel [Member]
Debt Instrument [Line Items]
Related debt paid off																	$ 13,500,000
Handysize Vessel [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Related debt paid off									$ 25,100,000
Handysize Vessel [Member] | ING Bank [Member]
Debt Instrument [Line Items]
Number of vessels financed | item															3
Number of vessels covered by Tranch I | item															2
Dry Bulk Carriers [Member] | Notes Payable - Variable Rate 2018, Tranche A [Member]
Debt Instrument [Line Items]
Business acquisition interest in acquiree														100.00%
Multi-Purpose Ice Strengthened [Member] | Capital One N.A. [Member]
Debt Instrument [Line Items]
Debt instrument principal amount												$ 15,700,000
Debt instrument term, years																		5 years
Final quarterly balloon payment												$ 4,700,000
Number of monthly payments | item												59
DVB Bank SE [Member] | Notes Payable - Fixed Rate 2020 [Member]
Debt Instrument [Line Items]
Interest rate	[4]															6.35%		6.35%	4.35%
Maturity date	[4]																	2020
Total principal due	[4]															$ 33,664,000		$ 33,664,000	$ 37,759,000
DVB Bank SE [Member] | Notes Payable - Variable Rate 2020 [Member]
Debt Instrument [Line Items]
Interest rate	[5]																		3.61%
Maturity date	[5]																	2020
Total principal due	[5]																		$ 24,812,000
DVB Bank SE [Member] | Loan Agreement [Member]
Debt Instrument [Line Items]
Interest rate				6.35%				4.35%
Early pre-payment amount included as restricted cash																$ 500,000		$ 500,000
Debt instrument principal amount								$ 38,500,000
Number of quarterly payments | item								24
Final quarterly balloon payment								$ 20,700,000
DVB Bank SE [Member] | New Loan Agreement [Member]
Debt Instrument [Line Items]
Interest rate							4.16%
Debt instrument principal amount							$ 32,000,000														$ 32,000,000
Final quarterly balloon payment							16,800,000
Related debt paid off						¥ 2.9	$ 24,000,000
Term for principal to be paid quarterly																		5 years
Amortization period																		10 years
RBS Asset Finance [Member] | Notes Payable - Variable Rate 2021 [Member]
Debt Instrument [Line Items]
Interest rate	[6]															3.99%		3.99%	2.9195%
Maturity date	[6]																	2021
Total principal due	[6]															$ 18,651,000		$ 18,651,000	$ 21,943,000
RBS Asset Finance [Member] | Loan Agreement [Member]
Debt Instrument [Line Items]
Debt instrument principal amount										$ 23,000,000
Basis spread on variable interest rate																1.00%
Number of monthly payments | item										84
RBS Asset Finance [Member] | Loan Agreement [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate										2.75%
DNB Bank [Member]
Debt Instrument [Line Items]
Bank debt owed to DnB ASA paid off										$ 11,400,000
Regions Bank [Member]
Debt Instrument [Line Items]
Interest rate																9.44%		9.44%	3.91%
Maturity date																		2017
Total principal due																$ 31,000,000		$ 31,000,000	$ 38,500,000
Regions Bank [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate			3.50%
Regions Bank [Member] | LIBOR [Member] | November 13, 2015 through June 30, 2016 [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate		9.25%
Regions Bank [Member] | LIBOR [Member] | July 1, 2016 through July 20, 2017 [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate		10.00%
Regions Bank [Member] | Notes Payable - Variable Rate 2018d [Member]
Debt Instrument [Line Items]
Interest rate	[7]															9.44%		9.44%	3.99%
Maturity date	[7]																	2017
Total principal due	[7]															$ 33,090,000		$ 33,090,000	$ 41,906,000
Regions Bank [Member] | Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility borrowing capacity																				$ 20,000,000
Regions Bank [Member] | Senior Secured Credit Facility [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument principal amount			$ 45,000,000
Regions Bank [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit																31,000,000		31,000,000
Regions Bank [Member] | Revolving Credit Facility [Member] | Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility borrowing capacity			20,000,000													7,200,000		7,200,000
Line of credit																7,200,000		7,200,000
Regions Bank [Member] | Revolving Credit Facility [Member] | Swingline Loans [Member]
Debt Instrument [Line Items]
Line of credit facility borrowing capacity			5,000,000													$ 5,000,000		$ 5,000,000
Regions Bank [Member] | Revolving Credit Facility [Member] | Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility borrowing capacity			$ 40,000,000

[1] Represents additional bank financing to fund the construction and renovation of our office building in New Orleans, Louisiana. This asset is included in assets held for sale at December 31, 2015 - refer to Note E - Assets Held for Sale.

[2] In December 2011, we entered into a variable rate financing agreement with Capital One N.A. for a five year facility totaling $15.7 million to finance a portion of the acquisition price of a multi-purpose ice strengthened vessel. This loan requires us to make 59 monthly payments with a final balloon payment of $4.7 million in January 2017.

[3] We entered into a variable rate financing agreement with ING Bank N.V, London branch in August 2010 for a seven year facility to finance the construction and acquisition of three handysize vessels. Pursuant to the terms of the facility, the lender agreed to provide a secured term loan facility divided into two tranches which corresponded to the vessel delivery schedule. Tranche I covered the first two vessels delivered with Tranche II covering the last vessel. Tranche I was fully drawn in the amount of $36.8 million, and Tranche II fully drawn at $18.4 million. We entered into a variable rate financing agreement with ING Bank N.V., London branch in June 2011 for a seven year facility to finance the acquisition of a capesize vessel and a supramax bulk carrier newbuilding, both of which we acquired a 100% interest in as a result of our acquisition of Dry Bulk. Pursuant to the terms of the facility, the lender agreed to provide a secured term loan facility divided into two tranches: Tranche A, fully drawn in June 2011 in the amount of $24.1 million, and Tranche B, providing up to $23.3 million of additional credit. Under Tranche B, we drew $6.1 million in November 2011 and $12.7 million in January 2012. In order to aid in the collateral value coverage covenant, both of the above facilities were merged into one facility without altering the debt maturities or terms of our indebtedness. Effective November 4, 2015, the interest rate was increased from LIBOR plus 2.5% to LIBOR plus 4.5%. For other changes to this credit facility, including the sales of the related vessels, refer to "Recent Financing Agreement Waivers and Amendments" below.

[4] We entered into a fixed rate financing agreement with DVB Bank SE, on August 26, 2014 in the amount of $38.5 million, collateralized by our 2007 PCTC at a rate of 4.35% with 24 quarterly payments with a final balloon payment of $20.7 million in August 2020. This loan requires us to pre-fund a one-third portion of the upcoming quarterly scheduled debt payment, which, at December 31, 2015, constituted $0.5 million and is included as restricted cash on our Consolidated Balance Sheet. Effective November 4, 2015, the interest rate increased from 4.35% to 6.35%. For other changes to the credit facility, refer to "Recent Financing Agreement Waivers and Amendments" below.

[5] As discussed in greater detail above, in April of 2015, we obtained a new loan with DVB Bank SE in the amount of $32.0 million. In connection with implementing our Strategic Plan, in December 2015 we used net proceeds from a vessel sale to pay off this loan in full.

[6] In August 2014, we paid off our $11.4 million loan with DNB Bank and obtained a new loan with RBS Asset Finance in the amount of $23.0 million collateralized by one of our 1999 PCTCs at a variable rate equal to the 30-day Libor rate plus 2.75% payable in 84 monthly installments with the final payment due August 2021. Late in 2015, this loan was amended to include an increase to the interest rate of 1.0%. For additional changes to this facility, refer to "Recent Financing Agreement Waivers and Amendments" below.

[7] Our original senior secured Credit Facility matured on September 24, 2018 and included a term loan facility in the principal amount of $45.0 million and a LOC in the principal amount up to $40.0 million. The LOC facility originally included a $20.0 million sublimit for the issuance of standby letters of credit and a $5.0 million sublimit for swingline loans. As discussed above, on November 13, 2015, the Credit Facility was amended. The maturity date was accelerated to July 20, 2017. Additionally, the interest rate increased from LIBOR plus 3.5% to LIBOR plus 9.25% which is effective from November 13, 2015 through June 30, 2016 and LIBOR plus 10.0% from July 1, 2016 through July 20, 2017. For other changes to the credit facility, refer to "Recent Financing Agreement Waivers and Amendments" below.