Fair Value Measurements (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2013 Interest rate contracts No longer qualified for hedge accounting treatment	Mar. 31, 2012 Interest rate contracts No longer qualified for hedge accounting treatment	Mar. 31, 2013 Interest rate Swap Agreement, one No longer qualified for hedge accounting treatment	May 08, 2008 Interest rate Swap Agreement, one No longer qualified for hedge accounting treatment	Mar. 31, 2013 Interest rate Swap Agreement, two No longer qualified for hedge accounting treatment	May 08, 2008 Interest rate Swap Agreement, two No longer qualified for hedge accounting treatment
Details of each remaining interest rate Swap Agreement
Amount of Loss Reclassified from Accumulated OCI into Income		$ 207	$ 301
Discontinued hedge's remaining balance included in Accumulated Other Comprehensive Loss		1
Notional Amount				$ 25,000	$ 45,000	$ 20,000	$ 40,000
Fixed Rate (as a percent)				3.78%		3.78%
Reference rate, description	90-day LIBOR