Short-Term Borrowings (Short Term Borrowing) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Short-term Debt [Line Items]
Short-term borrowings	$ 47,769	$ 51,643
Interest on short-term borrowings	74	103	262
Repurchase Agreements [Member]
Short-term Debt [Line Items]
Short-term borrowings	32,769	43,143	51,509
Short-term Debt, Average Outstanding Amount	37,386	41,542	50,115
Short-term Debt, Maximum Month-end Outstanding Amount	44,905	49,162	51,762
Interest on short-term borrowings	57	98	252
Short-term Debt, Weighted Average Interest Rate	0.15%	0.16%	0.41%
Short-term Debt, Weighted Average Interest Rate Period	0.15%	0.24%	0.50%
FHLB advances
Short-term Debt [Line Items]
Short-term borrowings	15,000	8,500	0
Short-term Debt, Average Outstanding Amount	13,240	5,525	8,712
Short-term Debt, Maximum Month-end Outstanding Amount	39,900	21,900	57,400
Interest on short-term borrowings	17	5	10
Short-term Debt, Weighted Average Interest Rate	0.15%	0.14%	0.00%
Short-term Debt, Weighted Average Interest Rate Period	0.12%	0.08%	0.11%
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Short-term borrowings	0	0	0
Short-term Debt, Average Outstanding Amount	15	47	69
Short-term Debt, Maximum Month-end Outstanding Amount	0	0	0
Interest on short-term borrowings	$ 0	$ 0	$ 0
Short-term Debt, Weighted Average Interest Rate	0.00%	0.00%	0.00%
Short-term Debt, Weighted Average Interest Rate Period	0.74%	0.74%	0.00%