Interest Rate Derivatives and Hedging Activities (Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance) (Details) - Cash Flow Hedging - Derivatives, net - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Amount of loss recognized in accumulated other comprehensive income (loss) from interest rate derivatives (effective portion)	$ (1,235)	$ (1,619)
Amount of loss recognized in loss on derivative instruments (ineffective portion, reclassifications of missed forecasted transactions and amounts excluded from effectiveness testing)	0	(4)
Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of loss reclassified from accumulated other comprehensive income (loss) into income as interest expense (effective portion)	$ (356)	$ (526)