Derivatives and Hedging Activity (Details 2) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Effect of derivative instruments on the Consolidated Statements of Operations
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total	$ 1,608,000	$ 1,897,000	$ 3,545,000	$ 3,752,000
Derivative Instruments, Gain (Loss) Recognized in Income, Net, Total	(3,000)	(7,000)	(5,000)	291,000
Cash Flow Hedging [Member]
Effect of derivative instruments on the Consolidated Statements of Operations
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income, Effective Portion, Net, Total	144,000	(1,533,000)	52,000	(3,492,000)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total	(1,608,000)	(1,897,000)	(3,545,000)	(3,752,000)
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net, Total	0	0	0	0
Derivative Instruments, Gain (Loss) Recognized in Income, Net, Total	(3,000)	(7,000)	(5,000)	291,000
Interest Rate Products [Member] | Interest Expense [Member] | Cash Flow Hedging [Member]
Effect of derivative instruments on the Consolidated Statements of Operations
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income, Effective Portion, Net, Total	144,000	(1,533,000)	52,000	(3,492,000)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total	(1,608,000)	(1,897,000)	(3,545,000)	(3,752,000)
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net, Total	$ 0	$ 0	$ 0	$ 0