Long-Term Debt (Schedule Of Long-Term Debt) (Details) (USD $)						0 Months Ended		1 Months Ended			3 Months Ended				3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended
	Mar. 31, 2014		Dec. 31, 2013		Sep. 24, 2013	Jun. 20, 2011 Notes Payable - Variable Rate 2018a [Member]	Jun. 20, 2011 Notes Payable - Variable Rate 2018b [Member]	Jan. 24, 2012 Notes Payable - Variable Rate 2018b [Member]	Nov. 30, 2011 Notes Payable - Variable Rate 2018b [Member]	Mar. 31, 2014 Notes Payable - Variable Rate 2020 [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018a [Member]		Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018a [Member]		Mar. 31, 2014 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018b [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018b [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2017 [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2017 [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018c [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018c [Member]	Mar. 31, 2014 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018d [Member]		Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018d [Member]		Mar. 31, 2014 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2020 [Member]		Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2020 [Member]		Mar. 31, 2014 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018e [Member]		Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018e [Member]		Mar. 31, 2014 Secured Line Of Credit [Member]		Dec. 31, 2013 Secured Line Of Credit [Member]		Sep. 24, 2013 Senior Secured Credit Facility [Member]	Sep. 24, 2013 Standby Letters Of Credit [Member]	Sep. 24, 2013 Swingline Loans [Member]	Jun. 20, 2011 ING Bank [Member] item
Debt Instrument [Line Items]
Interest rate (in hundredths)											2.7349%	[1]	2.7451%	[1]	2.74%	2.74%	2.5045%	2.5188%	2.9166%	2.9181%	2.7365%	[1]	2.7384%	[1]	2.89%	[2]	2.8964%	[2]	4.00%	[3]	3.75%	[3]	3.91%	[3]	3.67%	[3]
Maturity date											2018	[1]			2018		2017		2018		2018	[1]			2020	[2]			2018	[3]			2018	[3]
Total Principal Due	$ 194,113,000	[1]	$ 198,229,000	[1]							$ 14,602,000	[1]	$ 15,460,000	[1]	$ 44,160,000	$ 45,081,000	$ 10,823,000	$ 11,383,000	$ 12,070,000	$ 12,780,000	$ 16,337,000	[1]	$ 16,651,000	[1]	$ 31,246,000	[2]	$ 31,437,000	[2]	$ 43,875,000	[3]	$ 44,437,000	[3]	$ 21,000,000	[3]	$ 21,000,000	[3]
Less current maturities	(19,559,000)		(19,213,000)
Long-term debt - non-current	174,554,000		179,016,000
Interest rate swap , fixed interest rate (in hundredths)										2.065%
Effective, swaption interest rate (in hundredths)										3.715%
Term of financing agreement in years																																								7 years
Business acquisition interest in acquiree						100.00%
Proceeds from borrowings of line of credit						24,100,000	23,300,000	12,700,000	6,100,000
Number of tranches																																								2
Term loan facility principal amount																																					45,000,000
Line of credit					$ 50,000,000																																	$ 20,000,000	$ 5,000,000

[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 Cape Size vessel and a Handymax 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] 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 3.715%. The swap agreement is for the same term as the associated note payable.

[3] 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.