Derivative Instruments - Cash Flow Hedging (Details) (Cash Flow Hedging [Member], USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Effects of derivative instruments
Amount of Gain Recognized in OCI on Derivatives (Effective Portion)		$ (480,000)		$ (1,389,000)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	122,000	(390,000)	371,000	(1,149,000)
Previously held hedges			127,000
Interest Expense [Member]
Effects of derivative instruments
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	122,000	(390,000)	371,000	(1,149,000)
Interest Expense [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Effects of derivative instruments
Amount of interest expense reduction from ineffective derivative instrument	122,000	(390,000)
Interest Rate Contract [Member]
Effects of derivative instruments
Amount of Gain Recognized in OCI on Derivatives (Effective Portion)		(480,000)		(1,389,000)
Amount of interest payments reclassified to income statement	$ 0	$ 500,000	$ 0	$ 1,400,000