Interest Rate Derivative Agreements (Details) (USD $)	3 Months Ended
	Mar. 31, 2015
Bank of New York Mellon [Member]
Derivative [Line Items]
Derivative, Purchase Date	Sep. 02, 2010
Derivative Asset, Notional Amount	$ 31,936,667
Derivative, Fixed Interest Rate	3.00%
Derivative, Maturity Date at a point in time	Sep. 01, 2017
Deriviative at purchase price	921,000
Barclays Bank PLC [Member]
Derivative [Line Items]
Derivative, Purchase Date	Sep. 02, 2010
Derivative Asset, Notional Amount	31,936,667
Derivative, Fixed Interest Rate	3.00%
Derivative, Maturity Date at a point in time	Sep. 01, 2017
Deriviative at purchase price	845,600
Royal Bank of Canada [Member]
Derivative [Line Items]
Derivative, Purchase Date	Sep. 02, 2010
Derivative Asset, Notional Amount	31,936,667
Derivative, Fixed Interest Rate	3.00%
Derivative, Maturity Date at a point in time	Sep. 01, 2017
Deriviative at purchase price	928,000
Deutsche Bank [Member]
Derivative [Line Items]
Derivative, Purchase Date	Aug. 15, 2013
Derivative Asset, Notional Amount	93,305,000
Derivative, Fixed Interest Rate	1.50%
Derivative, Maturity Date at a point in time	Sep. 01, 2017
Deriviative at purchase price	793,000
SMBC Capital Markets, Inc [Member]
Derivative [Line Items]
Derivative, Purchase Date	Feb. 18, 2014
Derivative Asset, Notional Amount	41,250,000
Derivative, Fixed Interest Rate	1.00%
Derivative, Maturity Date at a point in time	Mar. 01, 2017
Deriviative at purchase price	230,500
SMBC Capital Markets, Inc-2 [Member]
Derivative [Line Items]
Derivative, Purchase Date	Feb. 18, 2014
Derivative Asset, Notional Amount	11,000,000
Derivative, Fixed Interest Rate	1.00%
Derivative, Maturity Date at a point in time	Mar. 01, 2017
Deriviative at purchase price	150,500
Barclays Bank PLC 1 [Member]
Derivative [Line Items]
Derivative, Purchase Date	Jul. 10, 2014
Derivative Asset, Notional Amount	31,565,000
Derivative, Fixed Interest Rate	3.00%
Derivative, Maturity Date at a point in time	Aug. 15, 2019
Deriviative at purchase price	315,200
Royal Bank of Canada-2 [Member]
Derivative [Line Items]
Derivative, Purchase Date	Jul. 10, 2014
Derivative Asset, Notional Amount	31,565,000
Derivative, Fixed Interest Rate	3.00%
Derivative, Maturity Date at a point in time	Aug. 15, 2019
Deriviative at purchase price	343,000
SMBC Capital Markets, Inc-3 [Member]
Derivative [Line Items]
Derivative, Purchase Date	Jul. 10, 2014
Derivative Asset, Notional Amount	31,565,000
Derivative, Fixed Interest Rate	3.00%
Derivative, Maturity Date at a point in time	Aug. 15, 2019
Deriviative at purchase price	$ 333,200