Derivatives (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net [Abstract]
Amortization of Interest Rate Protection Agreements	$ 571	$ 546	$ 1,111	$ 1,102
Interest Expense [Member]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net [Abstract]
Amortization of Interest Rate Protection Agreements	$ (571)	$ (546)	$ (1,111)	$ (1,102)