Borrowed Funds (Summary of Short Term Borrowings) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Borrowed Funds [Abstract]
Outstanding at year end	$ 39,257	$ 36,868
Weighted average interest rate at end of period	0.34%	0.64%
Maximum amount outstanding as of any month end	52,367	51,403
Average amount outstanding	$ 38,812	$ 41,728
Approximate weighted average rate during the period	0.34%	0.56%