Derivatives and Hedging Activities (Details) (USD $)	9 Months Ended	1 Months Ended				9 Months Ended
	Sep. 30, 2014	Jan. 31, 2012 Interest Rate Swap [Member]	Sep. 30, 2014 Designated as Hedging Instrument [Member] Interest Rate Swap [Member] Other Assets [Member]	Dec. 31, 2013 Designated as Hedging Instrument [Member] Interest Rate Swap [Member] Other Assets [Member]	Sep. 30, 2014 Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Interest Rate Swap [Member] Financial_Instrument	Sep. 30, 2014 Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Interest Rate Swap [Member] Interest Expense [Member]	Sep. 30, 2013 Designated as Hedging Instrument [Member] Cash Flow Hedging [Member] Interest Rate Swap [Member] Interest Expense [Member]
Derivative [Line Items]
Notional amount					$ 505,000,000
Settlement amount		3,539,000
Amount of loss reclassified from accumulated OCI into income (effective portion)		1,837,000				4,103,000	2,174,000
Expected amount of derivative related interest to be reclassified to interest expense over the next 12 months	5,118,000
Number of derivative instruments held					10
Derivative asset			3,305,000	4,439,000
Amount of gain (loss) recognized in OCI on derivatives (effective portion)						$ (5,237,000)	$ 6,349,000