Derivatives and Hedging Activities (Effect of Derivative Instruments on Consolidated Statement of Operations) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)	$ (1,500,000)	$ (8,306,000)	$ (12,335,000)
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(4,364,000)	(7,064,000)	(11,785,000)
Interest Expense
Derivative
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	(54,000)	(100,000)	(157,000)
Designated as Hedging Instrument | Interest Expense
Derivative
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(4,364,000)	(7,064,000)	(11,785,000)
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(54,000)	(100,000)	(157,000)
Designated as Hedging Instrument | Interest Rate Contract
Derivative
Unrealized (loss) gain from the effective portion of derivative instruments	(1,500,000)	(8,306,000)	(12,335,000)
Not Designated as Hedging Instrument
Derivative
Derivative Instruments, Gain (Loss) Recognized in Income, Net	0	(3,000)	(146,000)
Not Designated as Hedging Instrument | Interest Expense
Derivative
Derivative Instruments, Gain (Loss) Recognized in Income, Net	0	(3,000)	(146,000)
Parent Company [Member]
Derivative
Accumulated other comprehensive income (losses)	1,144,000	(1,589,000)	(412,000)	$ 108,000
Unrealized (loss) gain from the effective portion of derivative instruments	$ (1,500,000)	$ (8,306,000)	$ (12,335,000)