Derivative Instruments and Hedging Activities (Schedule of Gains or Losses Recognized on Derivative Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in OCI on Derivatives (Effective Portion)	$ 337	$ (1,828)	$ (2,753)	$ (2,454)
Amount of Loss Reclassified From Accumulated Other Comprehensive Loss to Net Income (Effective Portion)	(947)	(558)	(1,825)	(946)
Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in OCI on Derivatives (Effective Portion)	337	(1,828)	(2,753)	(2,454)
Interest Rate Swaps [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Loss Reclassified From Accumulated Other Comprehensive Loss to Net Income (Effective Portion)	$ (947)	$ (558)	$ (1,825)	$ (946)