Derivatives and Hedging Activities (Gains and Losses Related to Interest Rate Contract 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 and Hedging Activities Disclosure [Abstract]
Amount of loss reclassified from AOCI into interest expense during the period (effective portion)	$ (6,531)	$ (6,658)	$ (13,074)	$ (13,207)
Amount of gain (loss) recognized in income during the period (ineffective portion)	$ 0	$ 0	$ 0	$ 0