Derivatives (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended						1 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 2011 Interest Rate Swap	Dec. 31, 2011 2011 Interest Rate Swap	Jun. 30, 2011 2011 Interest Rate Swap	Jun. 30, 2012 2006 Interest Rate Swap	Dec. 31, 2011 2009 Interest Rate Swap	Jun. 30, 2012 2009 Interest Rate Swap	Jun. 30, 2011 2009 Interest Rate Swap
Derivative [Line Items]
Notional amount of interest rate derivatives					$ 93,500	$ 93,500	$ 0		$ 0	$ 0	$ 115,000
Fixed rate payments, interest rate					5.50%			7.125%		5.50%
Variable rate payment rate					1.75%			1.75%		1.75%
Fair value of collateral pledged to secure interest rate contracts	14,661		14,661
Incremental interest expense paid to interest rate swap counterparties	776	1,473	1,525	2,931
Purchase of underlying basis of trust preferred capital securities									$ 21,500