Derivative and Hedging Activities (Details) (Cash Flow Hedging [Member], Interest Rate Swap [Member], Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) Gain Recognized in OCL on Derivative Instruments (Effective Portion)	$ (4,398)	$ 111
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from AOCL into Net Income (Loss) (Effective Portion)	$ 1,070	$ (1,083)