Derivative Instruments (Narrative) (Details) (USD $)	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Derivative Instruments [Abstract]
Increase (decrease) in interest expense from derivatives	$ (761,000)	$ (331,000)
Interest rate swap	$ 5,094,000		$ 5,855,000

Fair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, and which are expected to be extinguished or otherwise disposed of after one year or beyond the normal operating cycle, if longer, net of the effects of master netting arrangements.

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+ Details