Out of Period Adjustment (Details) (USD $)	9 Months Ended	3 Months Ended			12 Months Ended	36 Months Ended
	Sep. 30, 2012	Jun. 30, 2012 Oslo Bulk AS [Member]	Mar. 31, 2012 Oslo Bulk AS [Member]	Sep. 30, 2011 Oslo Bulk AS [Member]	Dec. 31, 2012 Oslo Bulk AS [Member]	Dec. 31, 2011 Oslo Bulk AS [Member]	Sep. 30, 2013 Oslo Bulk AS [Member]	Jul. 31, 2011 Oslo Bulk AS [Member]
Schedule of Equity Method Investments [Line Items]
Equity investee ownership interest (in hundredths)							25.00%	25.00%
Amount of ineffectiveness on investment hedges		$ 674,000	$ 42,000
Out of period adjustments related to net charter revenues and lease termination				239,000		(324,000)
Decrease to pre-tax income					85,000
Increase to net income	2,835,000				631,000
Adjustment from out of period		$ 631,000