Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 trust	Dec. 31, 2011	Dec. 31, 2010
Significant Accounting Policies [Line Items]
Number of wholly owned trusts	17
Cash and cash equivalents general maturity	90 days
Other than temporary impairment losses total	$ 51,000	$ 190,000	$ 93,000
Unallocated amount as a percentage of allowance	10.00%
Percentage of loan portfolio is secured by real estate	79.00%
Federal Home Loan Bank stock	33,443,000	32,581,000
Impairment charges on servicing assets	0	0	0
Carrying value of Small Business Administration and Department of Agriculture servicing rights	498,000	584,000
Stock options and restricted stock awards generally vested period	5 years
Land and Building [Member]
Significant Accounting Policies [Line Items]
Equipment useful life, years	39 years
Maximum [Member] | Equipment [Member]
Significant Accounting Policies [Line Items]
Equipment useful life, years	10 years
Minimum [Member] | Equipment [Member]
Significant Accounting Policies [Line Items]
Equipment useful life, years	3 years
Investment In Federal Home Loan Bank Stock [Member]
Significant Accounting Policies [Line Items]
Federal Home Loan Bank stock	32,200,000	31,300,000
Federal home loan bank stock, minimum investment	$ 11,600,000