Derivative Financial Instruments (Schedule of Amounts Related to Interest Rate Derivatives Non-Hedging Interest Rate and Commodity Derivatives) (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Derivative Financial Instruments
Other non-interest income, Non-hedging commodity derivatives	$ 79	$ 26	$ 462	$ 46
Other non-interest expense, Non-hedging interest rate derivatives	(89)	59	(128)	78
Other non-interest income, Non-hedging interest rate derivatives	$ 462	$ 892	$ 736	$ 1,594