Derivative and Other Fair Value Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivatives, Fair Value [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	$ (1,300)	$ (1,492)
Amount of Gain/ (Loss) Recognized in Income on Hedged Item	1,300	1,492
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	(1,300)	(1,492)
Amount of Gain/ (Loss) Recognized in Income on Hedged Item	$ 1,300	$ 1,492
Hedged Item	Fixed rate debt	Fixed rate debt