Bank Premises and Equipment Rent Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Leased Assets [Line Items]
Gross rent expense	$ 653	$ 841	$ 1,049
Rental income	(46)	(41)	(42)
Net rent expense	607	800	1,007
Buildings and office space
Operating Leased Assets [Line Items]
Gross rent expense	486	665	581
Computer equipment
Operating Leased Assets [Line Items]
Gross rent expense	0	13	284
Other equipment and autos
Operating Leased Assets [Line Items]
Gross rent expense	$ 167	$ 163	$ 184