Derivatives (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Mark-to-Market on Interest Rate Protection Agreements (OCI) [Member]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net [Abstract]
Loss Recognized in OCI (Effective Portion)	$ 0	$ 990
Interest Expense [Member]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net [Abstract]
Amortization Reclassified from OCI into Income	$ (2,166)	$ (2,108)