Long-Term Debt (Schedule Of Long-Term Debt) (Details) (USD $)	0 Months Ended	1 Months Ended	3 Months Ended	0 Months Ended	12 Months Ended		1 Months Ended		0 Months Ended	6 Months Ended
	Sep. 24, 2013	Aug. 31, 2014	Sep. 30, 2014	Jun. 20, 2011	Dec. 31, 2014		Jan. 24, 2012	Nov. 30, 2011	Nov. 30, 2012	Dec. 31, 2014 item		Dec. 31, 2013		Aug. 26, 2014
Debt Instrument [Line Items]
Total Principal Due					$ 242,888,000					$ 242,888,000		$ 198,229,000
Less current maturities					(23,367,000)					(23,367,000)		(19,213,000)
Long-term debt - non-current					219,521,000					219,521,000		179,016,000
Proceeds from borrowings of line of credit	21,000,000
Maximum borrowing capacity	145,000,000
Bank debt owed to DnB ASA paid off		11,400,000	11,400,000
Notes Payable - Variable Rate 2018a [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)					2.7471%	[1]				2.7471%	[1]	2.7451%	[1]
Maturity date					2018	[1]
Total Principal Due					12,025,000	[1]				12,025,000	[1]	15,460,000	[1]
Business acquisition interest in acquiree				100.00%
Proceeds from borrowings of line of credit				24,100,000
Notes Payable - Variable Rate 2018b [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)												2.74%
Interest rate, minimum (in hundredths)					2.7312%
Interest rate, maximum (in hundredths)					2.7324%
Maturity date					2018
Total Principal Due					41,400,000					41,400,000		45,081,000
Proceeds from borrowings of line of credit				23,300,000			12,700,000	6,100,000
Notes Payable - Variable Rate 2017 [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)					2.505%					2.505%		2.5188%
Maturity date					2017
Total Principal Due					9,144,000					9,144,000		11,383,000
Notes Payable - Variable Rate 2021 [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)					2.9195%	[2]				2.9195%	[2]	2.9181%	[2]
Maturity date					2021	[2]
Total Principal Due					21,943,000	[2]				21,943,000	[2]	12,780,000	[2]
Notes Payable - Variable Rate 2018c [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)					2.735%	[1]				2.735%	[1]	2.7384%	[1]
Maturity date					2018	[1]
Total Principal Due					15,394,000	[1]				15,394,000	[1]	16,651,000	[1]
Notes Payable - Variable Rate 2020 [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)					3.61%	[3]				3.61%	[3]	2.8964%	[3]
Maturity date					2020	[3]
Total Principal Due					24,812,000	[3]				24,812,000	[3]	31,437,000	[3]
Interest rate swap , fixed interest rate (in hundredths)					2.065%					2.065%
Effective, swaption interest rate (in hundredths)					5.565%					5.565%
Notes Payable - Variable Rate 2018d [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)					3.99%	[4]				3.99%	[4]	3.75%	[4]
Maturity date					2018	[4]
Total Principal Due					41,906,000	[4]				41,906,000	[4]	44,437,000	[4]
Notes Payable - Fixed Rate 2020 [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)					4.35%	[5]				4.35%	[5]
Maturity date					2020	[5]
Total Principal Due					37,759,000	[5]				37,759,000	[5]
Note Payable - Mortgage [Member]
Debt Instrument [Line Items]
Total Principal Due					5,000	[6]				5,000	[6]
Secured Line Of Credit [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)					3.91%	[4]				3.91%	[4]	3.67%	[4]
Maturity date					2018	[4]
Total Principal Due					38,500,000	[4]				38,500,000	[4]	21,000,000	[4]
Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Total Principal Due					38,500,000					38,500,000
Term loan facility principal amount	45,000,000				45,000,000					45,000,000
Line of credit	50,000,000				50,000,000					50,000,000
Standby Letters Of Credit [Member]
Debt Instrument [Line Items]
Line of credit	20,000,000				20,000,000					20,000,000
Swingline Loans [Member]
Debt Instrument [Line Items]
Line of credit	5,000,000				5,000,000					5,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Term of financing agreement in years									5 years
ING Bank [Member]
Debt Instrument [Line Items]
Term of financing agreement in years					7 years
DVB Bank SE [Member] | Loan Agreement [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)			4.35%											4.35%
Term loan facility principal amount			38,500,000											38,500,000
Number of quarterly payments					24					24
Final quarterly balloon payment			20,700,000		20,700,000					20,700,000
RBS Asset Finance [Member] | Loan Agreement [Member]
Debt Instrument [Line Items]
Term loan facility principal amount		$ 23,000,000	$ 23,000,000
Basis spread on variable interest rate		2.75%	2.75%
Number of monthly payments					84					84

[1] We entered into a variable rate financing agreement with ING Bank N.V., London branch on June 20, 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 on June 20, 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.

[2] During August 2014, we paid off our $11.4 million loan with DnB ASA 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 of 30 day Libor rate plus 2.75% payable in 84 monthly installments with the final payment due August 2021.

[3] We have an interest rate swap agreement in place to fix the interest rate on our variable rate note payable expiring in 2020 at 2.065%. After applicable margin adjustments, the effective interest rate on this note payable is fixed at 5.565%. The swap agreement is for the same term as the associated note payable.

[4] As described in greater detail above, our senior secured Credit Facility matures on September 24, 2018 and includes a term loan facility in the principal amount of $45 million and a LOC in the principal amount up to $50 million. The LOC facility includes a $20 million sublimit for the issuance of standby letters of credit and a $5 million sublimit for swingline loans.

[5] 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.

[6] Represents consideration given in connection with the proposed construction financing relating to the building we plan to renovate as our new New Orleans headquarters building.