Long-Term Debt (Schedule Of Long-Term Debt) (Details) (USD $)	1 Months Ended							12 Months Ended				12 Months Ended				12 Months Ended		12 Months Ended				12 Months Ended				12 Months Ended								12 Months Ended		1 Months Ended						1 Months Ended			1 Months Ended
	Sep. 24, 2013	Dec. 31, 2013	Dec. 31, 2012	Mar. 25, 2011	Dec. 31, 2013 Notes Payable - Variable Rate 2020 [Member]	Dec. 31, 2013 Notes Payable - Variable Rate 2015 [Member]	Sep. 30, 2013 Notes Payable - Variable Rate 2015 [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018a [Member]		Dec. 31, 2012 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018a [Member]		Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018b [Member]	Dec. 31, 2012 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018b [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2017 [Member]	Dec. 31, 2012 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2017 [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018c [Member]	Dec. 31, 2012 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018c [Member]	Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018d [Member]		Dec. 31, 2012 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018d [Member]		Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2020 [Member]		Dec. 31, 2012 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2020 [Member]		Dec. 31, 2013 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2018e [Member]		Dec. 31, 2012 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2015 [Member]		Dec. 31, 2012 Senior Secured Credit Facility [Member] Notes Payable - Variable Rate 2017 B [Member]		Dec. 31, 2012 Line Of Credit Facility [Member]		Dec. 31, 2013 Secured Line Of Credit - New [Member]		Sep. 24, 2013 Senior Secured Credit Facility [Member] item	Dec. 31, 2013 Senior Secured Credit Facility [Member]	Sep. 24, 2013 Standby Letters Of Credit [Member]	Sep. 24, 2013 Swingline Loans [Member]	Nov. 30, 2012 Revolving Credit Facility [Member]	Nov. 30, 2012 Capital One N.A. [Member] Notes Payable - Variable Rate 2017 B [Member]	Jan. 24, 2012 ING Bank [Member]	Nov. 30, 2011 ING Bank [Member]	Jun. 20, 2011 ING Bank [Member] item	Jun. 30, 2011 ING Bank [Member] Notes Payable - Variable Rate 2018a [Member]	Jun. 30, 2011 ING Bank [Member] Notes Payable - Variable Rate 2018b [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)								2.7451%	[1]	2.809%	[1]	2.74%		2.5188%	2.559%	2.9181%	2.981%	2.7384%	[1]	2.8158%	[1]	2.8964%	[2]	1.8314%	[2]	3.75%	[3]	2.06%	[4]	2.709%	[3],[5]	3.9597%	[6]	3.67%	[3]
Interest rate, minimum (in hundredths)													2.81%
Interest rate, maximum (in hundredths)													2.85%
Maturity date								2018	[1]			2018		2017		2018		2018	[1]			2020	[2]			2018	[3]							2018	[3]
Total Principal Due		$ 198,229,000	$ 237,630,000					$ 15,460,000	[1]	$ 18,896,000	[1]	$ 45,081,000	$ 48,760,000	$ 11,383,000	$ 13,436,000	$ 12,780,000	$ 15,620,000	$ 16,651,000	[1]	$ 17,908,000	[1]	$ 31,437,000	[2]	$ 42,089,000	[2]	$ 44,437,000	[3]	$ 12,666,000	[4]	$ 30,000,000	[3],[5]	$ 38,255,000	[6]	$ 21,000,000	[3]		$ 21,000,000				$ 30,000,000
Less current maturities		(19,213,000)	(26,040,000)
Long-term debt - non-current		179,016,000	211,590,000
Interest rate swap , fixed interest rate (in hundredths)					2.065%	4.41%
Effective, swaption interest rate (in hundredths)					4.815%
Early pre-payment amount							13,300,000																																		25,500,000
Term of financing agreement in years																																								5 years	5 years			7 years
Business acquisition interest in acquiree				100.00%																																								100.00%
Proceeds from borrowings of line of credit	21,000,000																																									12,700,000	6,100,000		24,100,000	23,300,000
Number of tranches																																												2
Term loan facility principal amount																																				45,000,000
Line of credit																																				50,000,000		20,000,000	5,000,000
Additional term loan amount	50,000,000																																			50,000,000
Number of lenders																																				4
Lender commitments, minimum																																				15,000,000
Lender commitments, maximum																																				$ 30,000,000

[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 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 on January 24, 2012.

[2] We have a Yen 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 4.815%. The swap agreement is for the same term as the associated note payable.

[3] As described in greater detail above, on September 24, 2013, we entered into a senior secured Credit Facility. The Credit Facility matures on September 24, 2018 and includes a term loan facility in the principal amount of $45.0 million and a LOC, which allows for borrowing up to a principal amount of $50.0 million. The LOC facility includes a $20.0 million sublimit for the issuance of standby letters of credit and a $5.0 million sublimit for swingline loans. As of September 24, 2013, the Credit Facility had four lenders, each with commitments ranging from $15 million to $30 million. The facility carries an accordion feature, whereby an additional term loan up to $50.0 million may be advanced subject to certain financial requirements.

[4] We had an interest rate swap agreement in place to fix the interest rate on our variable rate note payable expiring in 2015 at 4.41%. Upon early repayment of approximately $13.3 million to close this credit facility, the interest rate swap was settled and terminated in the third quarter of 2013.

[5] We entered into a variable rate financing agreement with Capital One N.A. on November 30, 2012 for a five year facility totaling $30.0 million to finance a portion of the acquisition of UOS. This facility was fully drawn prior to the end of 2012. Upon execution of the new U.S. Senior Credit Facility, this credit facility was paid off in full. The early pre-payment amount was approximately $25.5 million.

[6] Our previously-existing unsecured line of credit agreement was paid off with the execution of the new secured credit facility on September 24, 2013.