Derivative Instruments (Statement of Operations Disclosures) (Details) (Interest Rate Contract [Member], Cash Flow Hedging, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Other Comprehensive Income (Loss)
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net
Amount of Gain/Loss Recognized in Accumulated Other Comprehensive Income on Derivative	$ 67	$ 0
Interest expense
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net
Amount of Gain/Loss Reclassified from Accumulated Other Comprehensive Income into Income	$ 90	$ 90