Financial Derivative Instruments (Schedule of Interest Rate Derivatives) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Financial Derivative Instruments [Abstract]
Unrealized losses on interest rate caps, Gross	$ (1,360)	$ (1,111)
Unamortized premium on interest rate caps, Gross	4,566	4,566
Total, Gross	3,206	3,455
Unrealized gain on interest rate caps, Net of Tax	(884)	(722)
Unamortized premium on interest rate caps, Net of Tax	2,968	2,968
Total, Net of Tax	$ 2,084	$ 2,246