Derivative Financial Instruments (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Sep. 17, 2012	Dec. 31, 2011
Derivative [Line Items]
Securities pledged as collateral	$ 210,327	$ 210,327		$ 211,988
Interest rate swap
Derivative [Line Items]
Fixed payment rate	3.795%	3.795%
Derivative, Description of Variable Rate Basis	three month LIBOR
Basis spread on floating rate	1.33%	1.33%
Cash pledged as collateral	1,873	1,873		1,861
Net settlement payment			156
Settlement payment paid during period		455
Estimated interest expense to be recognized during remainder of 2012	159	159
Estimated interest expense to be recognized over the next 12 months	632	632
Interest rate swap | U.S Government sponsored entities
Derivative [Line Items]
Securities pledged as collateral	$ 1,520	$ 1,520		$ 1,505