Derivatives and Hedging Activity (Details 2) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Effect of derivative instruments on the Consolidated Statements of Operations
Derivative Instruments, Gain (Loss) Recognized in Income, Net, Total	$ 86	$ (330)	$ 36	$ (647)
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) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total	(2,441)	(1,552)	(4,350)	(3,632)
Interest Rate Products [Member] | Other Expense [Member] | Cash Flow Hedging [Member]
Effect of derivative instruments on the Consolidated Statements of Operations
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net, Total		(1)		(1)
Interest Rate Products [Member] | Other Income/(Expense) [Member]
Effect of derivative instruments on the Consolidated Statements of Operations
Derivative Instruments, Gain (Loss) Recognized in Income, Net, Total	86	(330)	36	(647)
Interest Rate Products [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	(9,276)	(3,155)	(7,903)	(6,469)
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	(9,276)	(3,155)	(7,903)	(6,469)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total	(2,441)	(1,552)	(4,350)	(3,632)
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net, Total		$ (1)		$ (1)