Derivatives (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Derivative [Line Items]
Fair value of collateral pledged to secure interest rate contracts	$ 2,000		$ 2,000		$ 7,000
Incremental interest expense paid to interest rate swap counterparties	829	$ 840	2,500	$ 2,500
2011 Interest Rate Swap
Derivative [Line Items]
Notional amount of interest rate derivatives	$ 93,500		$ 93,500
Fixed rate payments, interest rate	5.50%		5.50%		5.50%
Variable rate payment rate	1.75%		1.75%		1.75%