Derivative Financial Instruments (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Derivative Financial Instruments [Abstract]
Unrealized gain on derivative	$ 1,086,000	$ 972,000	$ (1,437,000)
Realized loss on derivative	1,100,000	1,100,000
Reclassification of derivative-related losses into earnings during the next 12 months	$ 22,700,000